Dependence of Cd compositione on transient photovoltage characteristics in Hg1−xCdxTe photodiode

This paper presents an experimental study of transient photovoltage induced by the pulsed laser excitation in the HgCdTe pn junction photodiode. The excitation light source is a wavelength-tunable pulsed infrared laser. The photo-response shows an apparent negative valley during the first then evolves into a positive peak. An obviously magnitude decreasing of the negative valley can be observed as the Cd composition decrease. When the experiment temperature increase from liquid nitrogen to room temperature, only the positive peak can be observed even the photodiode illuminated by the strong laser intensity. This shows that the negative valley of the transient photovoltage can be attributed to the Schottky barrier at metal-semiconductor (M/S) interface, and the M/S interface photovoltaic effect influenced by the Cd composition and the temperature.