N. Bertru - Academia.edu (original) (raw)

Papers by N. Bertru

Research paper thumbnail of Effect of a lattice-matched GaAsSb capping layer on the structural properties of InAs/InGaAs/InP quantum dots

Journal of Applied Physics, 2010

The influence of a lattice-matched GaAsSb capping layer on the structural properties of self-asse... more The influence of a lattice-matched GaAsSb capping layer on the structural properties of self-assembled InAs quantum dots (QDs) grown on InP substrates is studied on the atomic scale by cross-sectional scanning tunneling microscopy. While lattice-matched In0.53Ga0.47As-capped QDs are clearly truncated pyramids, GaAs0.51Sb0.49-capped QDs grown under the same conditions look like full pyramids and exhibit a larger height, indicating that capping with GaAsSb reduces dot decomposition. Since there are no differences in strain between the two capping layers, this behavior is most likely related to the surfactant effect of Sb, which stabilizes the growth front and avoids adatom migration.

Research paper thumbnail of Problems relevant to the use of optical pyrometers for substrate temperature measurements and controls in molecular beam epitaxy

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1995

In molecular beam epitaxy an optical pyrometer is frequently used to determine substrate and epil... more In molecular beam epitaxy an optical pyrometer is frequently used to determine substrate and epilayer temperatures during the growth of semiconductors. This implies a calibration of the pyrometer and a correct analysis of its indications. In this article we discuss problems presented by this calibration. We first compare the temperatures measured on the sample holder and on several substrates ͑GaAs, InAs, GaSb͒ attached to it. Then we present examples of temperature variations recorded during the growth of AlSb and GaSb on GaSb or GaAs substrates. GaSb epilayers thicker than 0.1 m induce a 40°-60°decrease of the measured temperature. AlSb deposition on GaSb produces temperature oscillations. We discuss these variations in terms of apparent and true temperature variations.

Research paper thumbnail of A theoretical and experimental study of λ>2 μm luminescence of quantum dots on InP substrate

AIP Conference Proceedings, 2007

Theoretical and experimental studies of the electronic properties of InAs(Sb) quantum dots (QDs) ... more Theoretical and experimental studies of the electronic properties of InAs(Sb) quantum dots (QDs) grown by molecular beam epitaxy (MBE) on InP(100) substrate are presented. Eight-band k.p calculations including strain and piezoelectric effects are performed on InAs/InP(100) quantum dot (QD) structure to study the influence of the quantum dot height. Photoluminescence (PL) spectroscopy experiments show promising results. High arsine flow rate

Research paper thumbnail of Les applications laser des boîtes quantiques, Le cas des lasers à boîtes quantiques InAs réalisés sur substrats InP (311)B

Research paper thumbnail of Réalisation de boites quantiques pour l’application Laser : Le cas des boites quantiques InAs réalisés par épitaxie par jets moléculaires sur AlInAs

Research paper thumbnail of Semiconductor Nanostructure For 1.55 µm Optical Telecommunications Devices

Research paper thumbnail of InAs/InP quantum dots laser grown on (311)B substrates with AlGaInAs barriers

InAs quantum dots laser grown on (311)B InP substrates with AlGaInAs barriers have been fabricate... more InAs quantum dots laser grown on (311)B InP substrates with AlGaInAs barriers have been fabricated and studied. Laser emission up to 212 K is observed. At low temperature a decrease of the threshold current is observed with temperature. The electroluminescence spectra show a change in the spectrum shape and a shift with temperature which do not fit with the Varshni law. We interpret those measurements to a delayed thermalisation of carriers within quantum dot ensemble.

Research paper thumbnail of Lattice-matched GaAsPN/GaP single junction solar cell for high-efficiency tandem solar cells on silicon

Research paper thumbnail of Monolithic Integration of Diluted-Nitride III–V-N Compounds on Silicon Substrates: Toward the III–V/Si Concentrated Photovoltaics

Energy Harvesting and Systems, 2014

GaAsPN semiconductors are promising material for the development of high-efficiency tandem solar ... more GaAsPN semiconductors are promising material for the development of high-efficiency tandem solar cells on silicon substrates. GaAsPN diluted-nitride alloy is studied as the top-junction material due to its perfect lattice matching with the Si substrate and its ideal bandgap energy allowing a perfect current matching with the Si bottom cell. The GaP/Si interface is also studied in order to obtain defect-free GaP/Si pseudo-substrates suitable for the subsequent GaAsPN top junctions growth. Result shows that a double-step growth procedure suppresses most of the microtwins and a bi-stepped Si buffer can be grown, suitable to reduce the anti-phase domains density. We also review our recent progress in materials development of the GaAsPN alloy and our recent studies of all the different building blocks toward the development of a PIN solar cell. GaAsPN alloy with energy bandgap around 1.8 eV, lattice matched with the Si substrate, has been achieved. This alloy displays efficient photolumi...

Research paper thumbnail of Achievement of vertically stacked InAs quantum dots on InP emitting at 1.55 μm

Conference Proceedings. Eleventh International Conference on Indium Phosphide and Related Materials (IPRM'99) (Cat. No.99CH36362)

Due to the use of (311)B InP substrate we grew InAs SAQD with similar qualities to the InAs/GaAs ... more Due to the use of (311)B InP substrate we grew InAs SAQD with similar qualities to the InAs/GaAs system. In addition a method using a growth interruption under P2 over pressure makes the control of the PL peak emission of the quantum dots structure easy to monitor. Thus this peak position is tuned to 1.55 μm at room temperature. This

Research paper thumbnail of Improvement of Sb-based multiquantum well lasers by Coulomb enhancement

IEE Proceedings - Optoelectronics, 1999

Strained GaInAsSb/GaSb quantum wells, grown by molecular beam epitaxy on GaSb substrates, have ex... more Strained GaInAsSb/GaSb quantum wells, grown by molecular beam epitaxy on GaSb substrates, have exhibited laser emissions at 2. 3 5~ and 2. 6 5~ at 23°C with res ective threshold current densities of 0.6kA/cmP and 3kA/cm2. Taking into account the Coulomb attraction, induced by carrier injection, we explain why room temperature lasing is possible in these structures, which have a type-I1 band alignment. A comparison between experimental and simulated data including Coulomb enhancement shows the essential part played by the electrostatic confinement in these quantum well laser structures.

Research paper thumbnail of Cai, D., LL Zheng, H. Zhang, VL Tassev and DF Bliss, Modeling of gas phase and surface reactions in an aluminum nitride growth system 293 (2006) 136 Caroff, P., see Alghoraibi, I. 293 (2006) 263

Research paper thumbnail of Développement d'un cluster de croissance UHVCVD-MBE pour l'intégration pseudomorphique III-V/Si

Research paper thumbnail of Etude par TEM et DRX des défauts cristallins dans des couches épitaxiées par MBE de GaP sur Silicium (001)

Research paper thumbnail of Thorough structural and optical analyses of GaP-based heterostructures monolithically grown on silicon substrates for photonics on Si applications: toward the laser on silicon and high efficiency photovoltaics on silicon

Research paper thumbnail of <title>Mid-infrared GaSb-InAs-based multiple quantum well lasers</title>

In-Plane Semiconductor Lasers: from Ultraviolet to Mid-Infrared II, 1998

ABSTRACT We report GaInAsSb/GaSb multiple quantum well lasers with type-II band alignment operati... more ABSTRACT We report GaInAsSb/GaSb multiple quantum well lasers with type-II band alignment operating at room temperature. Basic properties of GaInAsSb/GaSb system in presence of strains are presented. Room temperature lasing has been achieved at wavelengths up to 2.65 micrometer. For the first time, stimulated emission has been obtained from a type-III quantum well structure at room temperature at 1.98 micrometer and 2.32 micrometer for the structures with 6- and 12-angstrom-thick InAs quantum wells, respectively. Modification of the band structure near interfaces of the type-II quantum wells due to carrier injection is shown to be a decisive factor allowing to obtain low threshold lasing in quantum well structures with indirect radiative recombination.

Research paper thumbnail of Excitons in strained (Ga,In)Sb/GaSb quantum wells

Physical Review B, 1997

ABSTRACT

Research paper thumbnail of Electronic and optical properties ofInAs∕InPquantum dots on InP(100) andInP(311)Bsubstrates: Theory and experiment

Physical Review B, 2006

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of InAsSb/InGaAs quantum nanostructures on InP (100) substrate: observation of 2.35 µm photoluminescence

physica status solidi (c), 2006

... References [1] JG Kim, L. Shterengas, RU Martinelli, and GL Belenky, Appl. Phys. Lett. 83, 19... more ... References [1] JG Kim, L. Shterengas, RU Martinelli, and GL Belenky, Appl. Phys. Lett. 83, 1926 (2003). [2] P. Adamiec, A. Salhi, R. Bohdan, A. Bercha, F. Dybala, W. Trzeciakowski, Y. Rouillard, and A. Joullié, Appl. Phys. Lett. 85, 4292 (2004). ...

Research paper thumbnail of InAs(Sb)/InP(100) quantum dots for mid-infrared emitters: observation of 2.35 µm photoluminescence

physica status solidi (c), 2006

... References [1] JG Kim, L. Shterengas, RU Martinelli, and GL Belenky, Appl. Phys. Lett. 83, 19... more ... References [1] JG Kim, L. Shterengas, RU Martinelli, and GL Belenky, Appl. Phys. Lett. 83, 1926 (2003). [2] P. Adamiec, A. Salhi, R. Bohdan, A. Bercha, F. Dybala, W. Trzeciakowski, Y. Rouillard, and A. Joulli??, Appl. Phys. Lett. 85, 4292 (2004). ...

Research paper thumbnail of Effect of a lattice-matched GaAsSb capping layer on the structural properties of InAs/InGaAs/InP quantum dots

Journal of Applied Physics, 2010

The influence of a lattice-matched GaAsSb capping layer on the structural properties of self-asse... more The influence of a lattice-matched GaAsSb capping layer on the structural properties of self-assembled InAs quantum dots (QDs) grown on InP substrates is studied on the atomic scale by cross-sectional scanning tunneling microscopy. While lattice-matched In0.53Ga0.47As-capped QDs are clearly truncated pyramids, GaAs0.51Sb0.49-capped QDs grown under the same conditions look like full pyramids and exhibit a larger height, indicating that capping with GaAsSb reduces dot decomposition. Since there are no differences in strain between the two capping layers, this behavior is most likely related to the surfactant effect of Sb, which stabilizes the growth front and avoids adatom migration.

Research paper thumbnail of Problems relevant to the use of optical pyrometers for substrate temperature measurements and controls in molecular beam epitaxy

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1995

In molecular beam epitaxy an optical pyrometer is frequently used to determine substrate and epil... more In molecular beam epitaxy an optical pyrometer is frequently used to determine substrate and epilayer temperatures during the growth of semiconductors. This implies a calibration of the pyrometer and a correct analysis of its indications. In this article we discuss problems presented by this calibration. We first compare the temperatures measured on the sample holder and on several substrates ͑GaAs, InAs, GaSb͒ attached to it. Then we present examples of temperature variations recorded during the growth of AlSb and GaSb on GaSb or GaAs substrates. GaSb epilayers thicker than 0.1 m induce a 40°-60°decrease of the measured temperature. AlSb deposition on GaSb produces temperature oscillations. We discuss these variations in terms of apparent and true temperature variations.

Research paper thumbnail of A theoretical and experimental study of λ>2 μm luminescence of quantum dots on InP substrate

AIP Conference Proceedings, 2007

Theoretical and experimental studies of the electronic properties of InAs(Sb) quantum dots (QDs) ... more Theoretical and experimental studies of the electronic properties of InAs(Sb) quantum dots (QDs) grown by molecular beam epitaxy (MBE) on InP(100) substrate are presented. Eight-band k.p calculations including strain and piezoelectric effects are performed on InAs/InP(100) quantum dot (QD) structure to study the influence of the quantum dot height. Photoluminescence (PL) spectroscopy experiments show promising results. High arsine flow rate

Research paper thumbnail of Les applications laser des boîtes quantiques, Le cas des lasers à boîtes quantiques InAs réalisés sur substrats InP (311)B

Research paper thumbnail of Réalisation de boites quantiques pour l’application Laser : Le cas des boites quantiques InAs réalisés par épitaxie par jets moléculaires sur AlInAs

Research paper thumbnail of Semiconductor Nanostructure For 1.55 µm Optical Telecommunications Devices

Research paper thumbnail of InAs/InP quantum dots laser grown on (311)B substrates with AlGaInAs barriers

InAs quantum dots laser grown on (311)B InP substrates with AlGaInAs barriers have been fabricate... more InAs quantum dots laser grown on (311)B InP substrates with AlGaInAs barriers have been fabricated and studied. Laser emission up to 212 K is observed. At low temperature a decrease of the threshold current is observed with temperature. The electroluminescence spectra show a change in the spectrum shape and a shift with temperature which do not fit with the Varshni law. We interpret those measurements to a delayed thermalisation of carriers within quantum dot ensemble.

Research paper thumbnail of Lattice-matched GaAsPN/GaP single junction solar cell for high-efficiency tandem solar cells on silicon

Research paper thumbnail of Monolithic Integration of Diluted-Nitride III–V-N Compounds on Silicon Substrates: Toward the III–V/Si Concentrated Photovoltaics

Energy Harvesting and Systems, 2014

GaAsPN semiconductors are promising material for the development of high-efficiency tandem solar ... more GaAsPN semiconductors are promising material for the development of high-efficiency tandem solar cells on silicon substrates. GaAsPN diluted-nitride alloy is studied as the top-junction material due to its perfect lattice matching with the Si substrate and its ideal bandgap energy allowing a perfect current matching with the Si bottom cell. The GaP/Si interface is also studied in order to obtain defect-free GaP/Si pseudo-substrates suitable for the subsequent GaAsPN top junctions growth. Result shows that a double-step growth procedure suppresses most of the microtwins and a bi-stepped Si buffer can be grown, suitable to reduce the anti-phase domains density. We also review our recent progress in materials development of the GaAsPN alloy and our recent studies of all the different building blocks toward the development of a PIN solar cell. GaAsPN alloy with energy bandgap around 1.8 eV, lattice matched with the Si substrate, has been achieved. This alloy displays efficient photolumi...

Research paper thumbnail of Achievement of vertically stacked InAs quantum dots on InP emitting at 1.55 μm

Conference Proceedings. Eleventh International Conference on Indium Phosphide and Related Materials (IPRM'99) (Cat. No.99CH36362)

Due to the use of (311)B InP substrate we grew InAs SAQD with similar qualities to the InAs/GaAs ... more Due to the use of (311)B InP substrate we grew InAs SAQD with similar qualities to the InAs/GaAs system. In addition a method using a growth interruption under P2 over pressure makes the control of the PL peak emission of the quantum dots structure easy to monitor. Thus this peak position is tuned to 1.55 μm at room temperature. This

Research paper thumbnail of Improvement of Sb-based multiquantum well lasers by Coulomb enhancement

IEE Proceedings - Optoelectronics, 1999

Strained GaInAsSb/GaSb quantum wells, grown by molecular beam epitaxy on GaSb substrates, have ex... more Strained GaInAsSb/GaSb quantum wells, grown by molecular beam epitaxy on GaSb substrates, have exhibited laser emissions at 2. 3 5~ and 2. 6 5~ at 23°C with res ective threshold current densities of 0.6kA/cmP and 3kA/cm2. Taking into account the Coulomb attraction, induced by carrier injection, we explain why room temperature lasing is possible in these structures, which have a type-I1 band alignment. A comparison between experimental and simulated data including Coulomb enhancement shows the essential part played by the electrostatic confinement in these quantum well laser structures.

Research paper thumbnail of Cai, D., LL Zheng, H. Zhang, VL Tassev and DF Bliss, Modeling of gas phase and surface reactions in an aluminum nitride growth system 293 (2006) 136 Caroff, P., see Alghoraibi, I. 293 (2006) 263

Research paper thumbnail of Développement d'un cluster de croissance UHVCVD-MBE pour l'intégration pseudomorphique III-V/Si

Research paper thumbnail of Etude par TEM et DRX des défauts cristallins dans des couches épitaxiées par MBE de GaP sur Silicium (001)

Research paper thumbnail of Thorough structural and optical analyses of GaP-based heterostructures monolithically grown on silicon substrates for photonics on Si applications: toward the laser on silicon and high efficiency photovoltaics on silicon

Research paper thumbnail of <title>Mid-infrared GaSb-InAs-based multiple quantum well lasers</title>

In-Plane Semiconductor Lasers: from Ultraviolet to Mid-Infrared II, 1998

ABSTRACT We report GaInAsSb/GaSb multiple quantum well lasers with type-II band alignment operati... more ABSTRACT We report GaInAsSb/GaSb multiple quantum well lasers with type-II band alignment operating at room temperature. Basic properties of GaInAsSb/GaSb system in presence of strains are presented. Room temperature lasing has been achieved at wavelengths up to 2.65 micrometer. For the first time, stimulated emission has been obtained from a type-III quantum well structure at room temperature at 1.98 micrometer and 2.32 micrometer for the structures with 6- and 12-angstrom-thick InAs quantum wells, respectively. Modification of the band structure near interfaces of the type-II quantum wells due to carrier injection is shown to be a decisive factor allowing to obtain low threshold lasing in quantum well structures with indirect radiative recombination.

Research paper thumbnail of Excitons in strained (Ga,In)Sb/GaSb quantum wells

Physical Review B, 1997

ABSTRACT

Research paper thumbnail of Electronic and optical properties ofInAs∕InPquantum dots on InP(100) andInP(311)Bsubstrates: Theory and experiment

Physical Review B, 2006

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of InAsSb/InGaAs quantum nanostructures on InP (100) substrate: observation of 2.35 µm photoluminescence

physica status solidi (c), 2006

... References [1] JG Kim, L. Shterengas, RU Martinelli, and GL Belenky, Appl. Phys. Lett. 83, 19... more ... References [1] JG Kim, L. Shterengas, RU Martinelli, and GL Belenky, Appl. Phys. Lett. 83, 1926 (2003). [2] P. Adamiec, A. Salhi, R. Bohdan, A. Bercha, F. Dybala, W. Trzeciakowski, Y. Rouillard, and A. Joullié, Appl. Phys. Lett. 85, 4292 (2004). ...

Research paper thumbnail of InAs(Sb)/InP(100) quantum dots for mid-infrared emitters: observation of 2.35 µm photoluminescence

physica status solidi (c), 2006

... References [1] JG Kim, L. Shterengas, RU Martinelli, and GL Belenky, Appl. Phys. Lett. 83, 19... more ... References [1] JG Kim, L. Shterengas, RU Martinelli, and GL Belenky, Appl. Phys. Lett. 83, 1926 (2003). [2] P. Adamiec, A. Salhi, R. Bohdan, A. Bercha, F. Dybala, W. Trzeciakowski, Y. Rouillard, and A. Joulli??, Appl. Phys. Lett. 85, 4292 (2004). ...