Highly Efficient Perovskite Solar Cells with Substantial Reduction of Lead Content.

Chong Liu,Cuiling Zhang,Yaohua Mai,Hongliang Li,Jiandong Fan

doi:10.1038/srep35705

Chong Liu, Cuiling Zhang + Show 3 more

Open Access

https://doi.org/10.1038/srep35705

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Journal: Scientific Reports	Publication Date: Oct 18, 2016
Citations: 90	License type: CC BY 4.0

Affiliation: Hebei University, Jinan University

Abstract

Despite organometal halide perovskite solar cells have recently exhibited a significant leap in efficiency, the Sn-based perovskite solar cells still suffer from low efficiency. Here, a series homogeneous CH3NH3Pb(1−x)SnxI3 (0 ≤ x ≤ 1) perovskite thin films with full coverage were obtained via solvent engineering. In particular, the intermediate complexes of PbI2/(SnI2)∙(DMSO)x were proved to retard the crystallization of CH3NH3SnI3, thus allowing the realization of high quality Sn-introduced perovskite thin films. The external quantum efficiency (EQE) of as-prepared solar cells were demonstrated to extend a broad absorption minimum over 50% in the wavelength range from 350 to 950 nm accompanied by a noteworthy absorption onset up to 1050 nm. The CH3NH3Pb0.75Sn0.25I3 perovskite solar cells with inverted structure were consequently realized with maximum power conversion efficiency (PCE) of 14.12%.

Highlights

Perovskite solar cells have transfixed researchers in the solar energy field since its power conversion efficiency (PCE) was increased up to 22.1% in only 6 years, which outperformed other photovoltaic technologies[1,2,3,4,5,6,7]
The CH3NH3Pb(1−x)SnxI3 (0 ≤x ≤ 1) perovskite thin films were prepared by a two-step solution-processed technique that was able to control the crystallization rate of CH3NH3SnI3, which solved the problem of uncontrollable crystal growth due to its habitual nature of easier crystallization even at room temperature[17]
The pure Sn-based perovskite thin film still suffered from the poor perovskite film quality and low coverage, which gave rise to a poor photovoltaic performance

Summary

Introduction

Perovskite solar cells have transfixed researchers in the solar energy field since its power conversion efficiency (PCE) was increased up to 22.1% in only 6 years, which outperformed other photovoltaic technologies[1,2,3,4,5,6,7]. The highest PCE of completely lead-free perovskite solar cells was only 6%, even for the Sn-involved perovskite solar cell, its maximum PCE still remained around 7%, which was not comparable to the lead-based perovskite solar cells that rose up to 22.1% recently In this scenario, it is enlightening to realize competitive photovoltaic properties using lead-free organic–inorganic compounds toward commercial applications of perovskite solar cells. It is enlightening to realize competitive photovoltaic properties using lead-free organic–inorganic compounds toward commercial applications of perovskite solar cells In this communication, we used DMSO as the solvent mediation to form the PbI2/(SnI2)∙(DMSO)x complexes, which gave rise to the formation of satisfied CH3NH3Pb(1−x)SnxI3 (0 ≤x ≤ 1) thin films. The tunable bandgap by different x values allowed realizing an efficient Sn-based inverted perovskite solar cell with a maximum PCE of 14.12%

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Conclusion