Non-linear behaviour of large-area avalanche photodiodes (original) (raw)

Characterization of large area avalanche photodiodes in X-ray and VUV-light detection

Journal of Instrumentation, 2007

The present manuscript summarizes novel studies on the application of large area avalanche photodiodes (LAAPDs) to the detection of X-rays and vacuum ultraviolet (VUV) light. The operational characteristics of four different LAAPDs manufactured by Advanced Photonix Inc., with active areas of 80 and 200 mm^2 were investigated for X-ray detection at room temperature. The best energy resolution was found to be in the 10-18% range for 5.9 keV X-rays. The LAAPD, being compact, simple to operate and with high counting rate capability (up to about 10^5/s), proved to be useful in several applications, such as low-energy X-ray detection, where they can reach better performance than proportional counters. Since X-rays are used as reference in light measurements, the gain non-linearity between 5.9 keV X-rays and light pulses was investigated. The gain ratio between X-rays and VUV light decreases with gain, reaching 10 and 6% variations for VUV light produced in argon (~128 nm) and xenon (~172 nm), respectively, for a gain 200, while for visible light (~635 nm) the variation is lower than 1%. The effect of temperature on the LAAPD performance was investigated. Relative gain variations of about -5% per Celsius degree were observed for the highest gains. The excess noise factor was found to be independent on temperature, being between 1.8 and 2.3 for gains from 50 to 300. The energy resolution is better for decreasing temperatures due mainly to the dark current. LAAPDs were tested under intense magnetic fields up to 5 T, being insensitive when used in X-ray and visible-light detection, while for VUV light a significant amplitude reduction was observed at 5 T.

Detection of VUV Light with Avalanche Photodiodes

https://www.intechopen.com/chapters/18837, 2011

Silicon avalanche photodiodes are alternative devices to photomultiplier tubes in photon detection applications, presenting advantages that include compact structure, capability to sustain high pressure, low power consumption, wide dynamic range and high quantum efficiency, covering a wider spectral range. Therefore, they provide a more efficient conversion of the scintillation light into charge carriers. Major drawbacks are lower gains, of few hundreds, higher detection limits and non-uniformities in the percent range. Windowless APDs with spectral sensitivity extended downto the VUV region (~120 nm) have been developed by API [1], RMD [2] and Hamamatsu [3]. They have been used as photosensors for scintillation light produced in noble gases [4-6] and liquids [7-10] for X- and γ-ray spectroscopy applications. Up to now, the main application of APDs as VUV detectors is aimed for a neutrinoless double beta decay experiment using high pressure xenon [6]. Wide band-gap semiconductor photodiodes such as GaN and SiC are also alternative to photomultiplier tubes in UV detection. However, compared to Si-APDs, they present smaller active area of the order of the mm2, with higher wafer non-uniformities, lower quantum efficiency and reduced spectral sensitivity in the VUV region (usually useful above 200 nm). On the other hand, they present some advantages, namely the lower biasing voltages, higher gains with lower leak currents, the solar blind capability. Recent reviews on these APDs can be found in [11-17] and references therein. Through the last decade, we have investigated the response characteristics of a large area APD from API to the scintillation VUV light produced in gaseous argon and xenon at room temperature [4,5]. The emission spectra for argon and xenon electroluminescence is a narrow continuum peaking at about 128 and 172 nm, respectively, with 10 nm FWHM for both cases [18], and corresponds to the lower limit of the APD spectral response. For the 128 and 172 nm VUV light from argon and xenon scintillation, the effective quantum efficiency, here defined as the average number of free electrons produced in the APD per incident VUV photon is 0.5 and 1.1, respectively, corresponding to a spectral sensitivity of about 50 and 150 mA/W [4,19]. In this chapter, we review and summarize the results of our investigation, namely the gain non-linearity between the detection of X-rays and VUV light [20], the gain dependence on temperature [21,22], the behaviour under intense magnetic fields [23], the minimum detection limit, i.e. the minimum number of photons detectable above the noise level, and the statistical fluctuations in VUV photon detection [24]. ... Cristina MB Monteiro, Luís MP Fernandes and Joaquim MF dos Santos Instrumentation Centre (CI), Physics Department, University of Coimbra ...

11 Detection of VUV Light with Avalanche Photodiodes

2018

Silicon avalanche photodiodes are alternative devices to photomultiplier tubes in photon detection applications, presenting advantages that include compact structure, capability to sustain high pressure, low power consumption, wide dynamic range and high quantum efficiency, covering a wider spectral range. Therefore, they provide a more efficient conversion of the scintillation light into charge carriers. Major drawbacks are lower gains, of few hundreds, higher detection limits and non-uniformities in the percent range. Windowless APDs with spectral sensitivity extended downto the VUV region (~120 nm) have been developed by API [1], RMD [2] and Hamamatsu [3]. They have been used as photosensors for scintillation light produced in noble gases [4-6] and liquids [7-10] for Xand γ-ray spectroscopy applications. Up to now, the main application of APDs as VUV detectors is aimed for a neutrinoless double beta decay experiment using high pressure xenon [6]. Wide band-gap semiconductor photo...

Response of large area avalanche photodiodes to low energy x rays

The Review of scientific instruments, 2012

For an experiment to study neutron radiative beta-decay, we operated large area avalanche photodiodes (APDs) near liquid nitrogen temperature to detect x rays with energies between 0.2 keV and 20 keV. Whereas there are numerous reports of x ray spectrometry using APDs at energies above 1 keV, operation near liquid nitrogen temperature allowed us to reach a nominal threshold of 0.1 keV. However, due to the short penetration depth of x rays below 1 keV, the pulse height spectrum of the APD become complex. We studied the response using monochromatic x ray beams and employed phenomenological fits of the pulse height spectrum to model the measurement of a continuum spectrum from a synchrotron. In addition, the measured pulse height spectrum was modelled using a profile for the variation in efficiency of collection of photoelectrons with depth into the APD. The best results are obtained with the collection efficiency model.