Glen Goh | Temasek Polytechnic (original) (raw)

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Papers by Glen Goh

Chemical Science, 2014

Non-close-packed breath figure arrays were observed to form at the periphery of close-packed arra... more Non-close-packed breath figure arrays were observed to form at the periphery of close-packed arrays. We propose a mechanism for their formation and show a proof-of-concept that these non-close-packed pore arrays are formed due to a reversal of breath figure formation, and hence introduce a novel route to the self-assembly of such non-close-packed structures.

Applied Surface Science, 2016

Langmuir, 2015

We report a one-step method of forming non-close-packed (NCP) pore arrays of micron- and submicro... more We report a one-step method of forming non-close-packed (NCP) pore arrays of micron- and submicron-pores using chloroform-based solutions of polystyrene acidified with hydrogen bromide for breath figure (BF) patterning. As breath figure patterning takes place, water vapor condenses onto the polystyrene solution, forming water droplets on the solution surface. Concurrently, preferential ion partitioning of hydrogen bromide leads to positively charged water droplets which experience inter-droplet electrostatic repulsion. Self-organization of charged water droplets under surface flow, and subsequent evaporation of the droplet templates result in ordered BF arrays with pore separation-to-diameter (L/D) ratios of up to 16.5. Surface potential scans support that preferential ion partitioning of HBr has taken place. Radial distribution functions and Voronoi polygon analysis of pore arrays show that they possess a high degree of conformational order. Past fabrication methods of NCP structures typically require multi-step processes. In contrast, we have established a new route for facile self-assembly of previously inaccessible patterns, which comprises of only a single operational step.

ACS Applied Materials & Interfaces, 2015

The effect of inserting an SU-8 dielectric interlayer into inverted bulk heterojunction (BHJ) org... more The effect of inserting an SU-8 dielectric interlayer into inverted bulk heterojunction (BHJ) organic solar cells (OSCs) was studied. Insertion of an ultrathin layer of SU-8 between the zinc oxide (ZnO) electron transport layer and the photoactive layer resulted in a smoother interface and a 14% enhancement in power conversion efficiency. The properties of devices with and without an SU-8 interlayer were investigated using transient photovoltage (TPV) and double injection (DoI) techniques, and it was found that devices with SU-8 show longer carrier lifetimes and greater mobility-lifetime (μ-τ) products than those without. Devices with SU-8 were also found to have improved stability. The results indicate that the insertion of an SU-8 interlayer reduces the recombination rate for photogenerated carriers without affecting the charge transport properties, improving overall performance and stability.

Materials Chemistry and Physics, 2014

h i g h l i g h t s WO 3 photoanodes were prepared by reactive sputtering in Ar and O 2 mixtures.... more h i g h l i g h t s WO 3 photoanodes were prepared by reactive sputtering in Ar and O 2 mixtures. Furnace annealed films were monoclinic WO 3 with nanocrystalline grain sizes. Photocurrent of 4.1 mA cm À2 obtained from combination of high Ar and O 2 flow rates. Flow rate combinations affect structural and electrical properties of photoanodes.

Acs Applied Materials Interfaces, Feb 6, 2015