GaAs/Al0.8Ga0.2As avalanche photodiodes for soft X-ray spectroscopy

R.B. Gomes, C.H. Tan, X. Meng, J.P.R. David, J.S. Ng
2014 Journal of Instrumentation  
The soft X-ray spectroscopic performance of a GaAs/Al 0.8 Ga 0.2 As Separate Absorption and Multiplication (SAM) APD was assessed at room temperature using a 55 Fe source. An energy resolution of 1.08 keV (FWHM) was achieved for the 5.9 keV X-rays, at an avalanche gain of 3.5. The avalanche gain also improved the minimum detectable energy from 4.8 keV at unity gain to about 1.5 keV at a gain of 5. Through avalanche statistics analyses, we confirmed that (i) the APD's FWHM was degraded by X-ray
more » ... hoton absorption within the avalanche region, and (ii) photon absorption in/near the n-cladding layer contributed to an undesirable secondary peak in the spectrum.
doi:10.1088/1748-0221/9/03/p03014 fatcat:y5hy3skn55dhxftcjbpeokqjsi