Doping profile engineering and trap dynamics in perovskite solar cells: a capacitance-based simulation study

Abstract This study presents a comprehensive simulation-based analysis of how doping profile engineering influences the performance of perovskite solar cells. Three different doping (graded) profiles viz., linear grading, exponential grading and parabolic grading were investigated using SCAPS-1D to analyse their effects on charge generation and recombination, electric field distribution, and dielectric behaviour. The results demonstrate that exponential doping enhances electric field concentration at interfaces, promoting efficient charge extraction, while parabolic doping provides symmetric field distribution and balanced carrier collection, leading to minimal recombination losses. Analysis of frequency and apparent doping concentration offered substantial information about the dynamics of bulk and interface traps. Dielectric loss tangent analysis assessed trap response time which demonstrated exponential doping aids faster trap relaxation (10 −13 s), implying enhanced interface quality and decreased dielectric losses. Furthermore, interface defect simulations at the ETL/absorber interface validated the significant role of different traps in modeling the device’s frequency dependent behaviour. These findings demonstrate that tailored doping profiles not only alter internal electric field and carrier dynamics but also persuasively influence trap related dielectric properties. This work underscores the importance of doping engineering for optimizing the electrical and dielectric response of PSCs, offering valuable design strategies for enhancing their operational performance and stability.