Numerical evaluation and optimization of high sensitivity Cu₂CdSnSe₄ photodetector

Copper cadmium tin selenide (Cu₂CdSnSe₄) based photodetector (PD) has been explored with the solar cell capacitance simulator (SCAPS-1D). Herein, cadmium sulfide (CdS) and molybdenum disulfide (MoS₂) are used as a window and back surface field (BSF) layers, respectively. The physical attributes, such as width, carrier density and bulk defects have been adjusted to attain the optimal conditions. In an optimized environment, the performance parameters of the Cu₂CdSnSe₄ (CCTSe) PD e.g. open circuit voltage (V_OC), short circuit current (J_SC), responsivity, and detectivity are determined as 0.76 V, 45.57 mA/cm², 0.72 A/W and 5.05 × 10¹⁴ Jones, respectively without a BSF layer. After insertion of the BSF layer, the performance of the CCTSe PD is significantly upgraded because of the production of high built-in potential which rises the magnitude of V_OC from 0.76 V to 0.84 V. For this reason, the responsivity and detectivity of CCTSe PD are also grows with the value of 0.84 A/W and 2.32 × 10¹⁵ Jones, respectively that indicate its future potential.