Interfacial modification of perovskite solar cells via Cs2CO3: Computational and experimental approach

Abstract

Interfacial materials in perovskite solar cells (PSCs) between the absorber layer and charge selective layers are stimulants to boost performance and long-term stability. Incorporation of a low-temperature processed passivating agent at electron selective layer/perovskite interface can enhance the performance of PSCs, however, the interface at SnO2/(FAPbI3)0.85(MAPbBr3)0.15 suffers from surface phenomena that retard the overall performance of the PSCs. By adopting a synergistic approach, drift-diffusion simulation, and experimental validation we unravel the interaction of the passivation layer at electron selective layer/perovskite. Firstly, we elucidated the impact of defect density (Nt) at electron selective layer/perovskite and the conduction band of SnO2 using drift-diffusion simulation to yield a power conversion efficiency of 23.18 %. Secondly, we validate the simulation trend experimentally, by depositing the Cs2CO3 passivation layer on the top of the electron selective layer. The impact of Cs2CO3 on electro-optical properties, charge collection, and recombination rate at the interfaces of PSCs was unraveled. The PSC fabricated with Cs2CO3 treatment achieves a higher open-circuit voltage, Voc ~1090 mV. Our findings put forward a combinatorial protocol of drift-diffusion simulation and experimental studies to address the interfacial issues in PSCs.

Optimization of fluorinated interfacial layers with minimal surface coverage for hybrid perovskite materials

“…Numerous recent studies have revealed that the structure–activity relationship in perovskite surface passivating agents is not straightforward, 20 a ,22 and that the modification of the electronic properties or operational lifetime may result from effects that are specific to individual systems. 23 For example, when comparing the effect of 4-fluorophenethylammonium iodide (F-PEAI) 24 with its non-fluorinated analogue (PEAI), 8 a it was observed that F-PEAI-treated devices show enhanced stability when exposed to humidity.…”

Transition of Working Modes in Organic Photodetectors: Tuning the Electrode Work Function for Photodiode‐to‐Photoconductor Switching

“…Good performances in terms of reducing dark current density can be achieved in sandwich structure OPDs with the presence of an electrode buffer layer. Electrode buffer layers composed of various wide bandgap n-type metal oxides, such as ZnO, [25,26] TiO 2 , [27,28] and Cs 2 CO 3 , [29,30] have often been utilized in optoelectronic devices. Cs 2 CO 3 , in particular, has gained popularity due to its low cost, high electron mobility, and high transmittance.…”

Dual Function Modification of Cs2CO3 for Efficient Perovskite Solar Cells

“…Cesium carbonate (Cs 2 CO 3 ) is an excellent interface modification material widely used in organic light emitting diodes (OLED), organic solar cells (OSCs), organic field-effect transistors (OFET) and other devices. Cs 2 CO 3 can also be used as an interfacial passivation layer for ETL/perovskite to improve the efficiency of perovskite solar cells by reducing the recombination rate at the interface [9]. We have used Cs 2 CO 3 to electrically modify the electron transport layer (ETL) of p-i-n type PeSCs and improved device efficiency [10].…”