SCAPS-1D simulation of high-performance NaZn 0.7 Ag 0.3 Br 3 double perovskite solar cells with optimized transport layers

Abstract This study presents a comprehensive SCAPS-1D simulation of a lead-free double-perovskite solar cell based on NaZn 0.7 Ag 0.3 Br 3 as the absorber layer. Various electron transport layers (CdZnS, MZO, Nb 2 O 5 , and SnS 2 ) were systematically evaluated to optimize device performance. Among the investigated configurations, the FTO/SnS 2 /NaZn 0.7 Ag 0.3 Br 3 /CuAlO 2 /Pt structure exhibited superior photovoltaic characteristics due to improved band alignment and reduced recombination losses. Under ideal radiative-loss-free conditions (B = 0), a maximum power conversion efficiency (PCE) of 30.56% was obtained. However, after incorporating a realistic radiative recombination coefficient (B = 2.3 × 10 −9 cm 3 /s), the optimized device achieved a PCE of 29.92%, with minimal variation in short-circuit current density and a moderate reduction in open-circuit voltage. The results confirm that the proposed lead-free perovskite configuration maintains strong photovoltaic performance under physically realistic recombination conditions, highlighting its potential for high-efficiency and environmentally benign solar cell applications.