The role of interface energetics in Sb₂Se₃ thin film solar cells

Abstract

Interface energetics in heterojunction solar cell device comprises energy level discontinuity and energy band alignment at interfaces with considerable influence onphotovoltaic action viz photogeneration, separation and collection of charge carrier in a solar cell. We comprehensively discussed how the energy level alignment at the Sb2Se3/CdSinterfaces affects the charge recombination and device performance. The design parameters for controlling interface discontinuity and energy level alignment are the work function of contact at the contact-absorber interface, electron affinity for conduction band offset at the Sb2Se3-CdS interface, doping profile in absorber and buffer for Fermi-level positioning at the interface, and defects at the interface of Sb2Se3/CdS interface. We have compiled the optimal ranges for these controlling parameters, which enable us to achieve theoretically ideal values of energy level alignment and energetics, leading to maximized device performance.