Analyzing the Effect of Planar and Inverted Structure Architecture on the Properties of MAGeI3 Perovskite Solar Cells

Charge transport layers (CTLs) have remarkable influence on the stability and efficiency of perovskite cells (PSCs). Different CTL combination used with the perovskite forms unique energy band alignment and electric field. They have significant effects on the optoelectrical properties of PSC. Identifying the right CTL for perovskite is crucial. Herein, the PSC of CH3NH3GeI3 is modeled in SCAPS-1D with 13 CTLs. Because of their carrier mobility, chemical stability, and electric/thermal conductivity, copper, kesterite, and carbon CTL have been selected. The PSC is analyzed in planar (n-i-p) and inverted (p-i-n). A systematic approach has been adopted to analyze the influence of CTL on the quantum efficiency, absorption, transmissivity, band alignment, electric field, recombination, and I-V characteristics in both architectures. To further enhance the efficiency, design optimization of layer thickness and doping has been carried out. Moreover, the effect of defects, temperature, reflection, and work functions on the performance of PSC has also been studied. Based on the results, phenyl-C-61-butyric acid methyl ester (PCBM) performs better in planar, while C-60 performs better in inverted. Most of the Cu hole-transport layers (HTLs) perform better in inverted architecture, while most of the kesterite HTLs perform better in planar architecture. The best-performing p-i-n structure is PCBM/per/CuAlO(3 )with power conversion efficiency (PCE) of 24.32%, while the best n-i-p is C60/Per/CuAlO2 with PCE of 14.82%.