• Podzorov, V.
• Zhu, X. -Y.
• Zakhidov, A.
• Yi, Hee Taek
• Wu, X.
• Rodionov, Y. I.
• Tikhonov, K. S.
• Chen, Y.
• Gartstein, Y. N.
• Haroldson, R.

Abstract

Impressive performance of hybrid perovskite solar cells reported in recent years still awaits a comprehensive understanding of its microscopic origins. In this work, the intrinsic Hall mobility and photocarrier recombination coefficient are directly measured in these materials in steady-state transport studies. The results show that electron-hole recombination and carrier trapping rates in hybrid perovskites are very low. The bimolecular recombination coefficient (10^–11 to 10^–10 cm³ s^–1) is found to be on par with that in the best direct-band inorganic semiconductors, even though the intrinsic Hall mobility in hybrid perovskites is considerably lower (up to 60 cm² V^–1 s^–1). Measured here, steady-state carrier lifetimes (of up to 3 ms) and diffusion lengths (as long as 650 μm) are significantly longer than those in high-purity crystalline inorganic semiconductors. As a result, we suggest that these experimental findings are consistent with the polaronic nature of charge carriers, resulting from an interaction of charges with methylammonium dipoles.

Topics

• perovskite
• impedance spectroscopy
• mobility
• semiconductor
• mass spectrometry
• photoconductivity