Minimizing Voltage Loss in Efficient All-Inorganic CsPbI₂Br Perovskite Solar Cells through Energy Level Alignment

Abstract

All-inorganic CsPbI2Br, prized for its strong stability against thermal aging and light soaking, has attracted intensive attention. However, a large energy loss results from the serious energy level offset of 1.05 eV between CsPbI2Br and Spiro-MeOTAD, hindering the further efficiency improvement of perovskite solar cells. To address this issue, a moderate energy level (CsPbI2Br)1–x (CsPbI3) x layer has been introduced at the interface between CsPbI2Br and Spiro-MeOTAD to form a graded energy level alignment, the interpolation of which has offered the energy level gradient for reducing the resistance of hole transport. Correspondingly, the energy level tailoring has minimized the energy loss, and a remarkable V OC improved from 1.12 to 1.32 V, which is one of the highest values for CsPbI2Br-based solar cells. A relatively good thermal stability has also been validated. These good performances indicate that setting an intermediate energy level alignment will be a potential strategy for idealized device architecture to minimize energy loss.

Suppressing Defects‐Induced Nonradiative Recombination for Efficient Perovskite Solar Cells through Green Antisolvent Engineering

“…Organic-inorganic hybrid halide perov skites, combining broad/tunable photo absorption, [1] high carrier mobilities/ diffusion length, [2,3] and weak exciton binding energy, [4] have intrigued exten sive attention for various high perfor mance optoelectronic applicants, such as perovskite solar cells (PSCs), [5] perovskite lightemitting diodes (PLEDs), [6] and perovskite photodetectors. [7] Due to the rapid evolution of power conversion effi ciency (PCE), PSCs have achieved great interests, with the stateoftheart certi fied PCE exceeding 25%.…”

Guanidinium Passivation for Air‐Stable Rubidium‐Incorporated Cs(1 − x)RbxPbI2Br Inorganic Perovskite Solar Cells

“…All‐inorganic perovskite solar cells (PSC) have attracted significant attention as one of promising template to solve the instability of organic–inorganic PSC since the first report in 2014 . To date, commonly used inorganic perovskite materials in PSC include CsPbI 3 , CsPbBr 3 , and mixed‐halide CsPbI (3 − y ) Br y , where y is the molar ratio of bromine in the precursor . Among them, cubic α‐phase CsPbI 3 has the narrowest bandgap of ≈1.73 eV, delivering a record device efficiency exceeding 19% .…”

Effective Surface Treatment for High-Performance Inverted CsPbI2Br Perovskite Solar Cells with Efficiency of 15.92%

“…One origin for V oc loss is the energy level mismatch between charge-transporting layers (CTLs) and CsPbI 2 Br, which would influence carrier transport and cause interfacial energy loss [23][24][25]. At present, researches have proposed interface engineering with well-matched CTLs to ameliorate interfacial energy loss and obtained considerable ameliorations [26,27].…”