Electron-hole diffusion lengths >175 μm in solution-grown CH₃NH₃PbI₃ single crystals

Authors

Qingfeng Dong, University of Nebraska-LincolnFollow
Yanjun Fang, University of Nebraska-LincolnFollow
Yuchuan Shao, University of Nebraska-Lincoln
Padhraic Mulligan, Ohio State University
Jie Qiu, Ohio State University
Lei Cao, Ohio State University
Jinsong Huang, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2015

Citation

Science sciencemag.org/content/early/recent / 29 January 2015 / Page 1 / 10.1126/science.aaa5760

Comments

Used by permission

Abstract

Long, balanced electron and hole diffusion lengths greater than 100 nanometers in polycrystalline CH₃NH₃PbI₃ are critical for highly efficient perovskite solar cells. We report that the diffusion lengths in CH₃NH₃PbI₃ single crystals grown by a solution-growth method can exceed 175 μm under 1 sun illumination and exceed 3 mm under weak light for both electrons and holes. The internal quantum efficiencies approach 100% in 3 mm-thick single crystal perovskite solar cells under weak light. These long diffusion lengths result from greater carrier mobility, lifetime and dramatically smaller trap densities in the single crystals than polycrystalline thin-films. The long carrier diffusion lengths enabled the use of CH₃NH₃PbI₃ in radiation sensing and energy-harvesting through gammavoltaic effect with an efficiency of 3.9% measured with an intense cesium-137 source.