Quantifying The Effects of Interface Defect Density on Charge Transport in CsPb0.625Zn0.375I2Br Solar Cells

In current era of green energy, technology is shifting toward usability of solar energy. Among the popularly used semiconductor materials in photovoltaic devices, perovskite material has been investigated on large scale due to its excellent optical performance. The photovoltaic performance (PV) of perovskite-based solar cells (PSC) has demonstrated exceptional performance in solar cell. Hybrid perovskite material possess high carrier life time, absorption co-efficient and diffusion length. In addition, it has feasibility to tune bandgaps to absorb different wavelengths. However, lead present in hybrid perovskite compounds is hazardous for environment. Also presence of organic cation is the main cause of thermal instability in hybrid perovskite. This study primarily aims to explore all inorganic halide perovskites (IHP) in photovoltaic cell. Due to outstanding optical performance and thermal stability of IHP materials, interest of researchers is shifting toward this material. The proposed design uses a low-lead IHP CsPb
0.625
Zn
0.375
I
2
Br, in the active layer of PSC structure. The device structure has simulated using simulator SCAPS-1D to verify the impact of interface defect density (IDD) at TiO2/ CsPb
0.625
Zn
0.375
I
2
Br and CsPb
0.625
Zn
0.375
I
2
Br / Spiro-MeOTAD interface. The IDD is varied in 7 logarithmic steps (10
¹²
cm
^-2
- 10
¹⁸
cm
^-2
). Obtained results indicate the degradation in photovoltaic performance with increase in IDD. It has been noticed from the simulated results that power conversion efficiency (PCE) 22.96% to 16.58% with increase in IDD. The same impact is also observed on short circuit current density (JSC), open circuit voltage (VOC) and fill factor (FF), it decreases from 35.03 mA/cm
²
to 33.88 mA/cm
²
, 0.80 V to 0.61 V and 83.55 % to 79.92 % respectively.