Strain effects in Hg1−xCdxTe (x∼0.2) photovoltaic arrays

The effect of stress and strain on the performance of Hg1−xCdxTe (x∼0.2) photovoltaic arrays was studied both in the dark and under illumination. Stress, external as well as internal, affects the current–voltage characteristic of the photodiode. The combined action of illumination and strain yields an anomalous response to light absorption in the device. A model is conceived wherein the photodiode and guard ring are treated as a metal‐insulator semiconductor field effect transistor (MISFET). Stress developed in the vicinity of small contact windows causes n‐type damage, which brings about a forward bias in the device. The effect of strain on the reverse current of the photodiode is explained by a change in the n‐channel conductivity of the MISFET. This change is caused by charges which are due either to a piezoelectric effect or n‐type damage. Using this model observed phenomena in Hg1−xCdxTe photovoltaic arrays are explained, as due to internal stresses originating from wafer deformation.