Unbalanced Hole and Electron Diffusion in Lead Bromide Perovskites

被引：111

作者：

Elbaz, Giselle A. ^{[1
]}

Straus, Daniel B. ^{[2
]}

Semonin, Octavi E. ^{[1
,7
]}

Hull, Trevor D. ^{[1
]}

Paley, Daniel W. ^{[1
,6
]}

Kim, Philip ^{[3
]}

Owen, Jonathan S. ^{[1
]}

Kagan, Cherie R. ^{[2
,4
,5
]}

Roy, Xavier ^{[1
]}

机构：

[1] Columbia Univ, Dept Chem, New York, NY 10027 USA

[2] Univ Penn, Dept Chem, Philadelphia, PA 19104 USA

[3] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA

[4] Univ Penn, Dept Elect & Syst Engn, Philadelphia, PA 19104 USA

[5] Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA

[6] Columbia Univ, Columbia Nano Initiat, New York, NY 10027 USA

[7] Alta Devices, 545 Oakmead Pkwy, Sunnyvale, CA 94085 USA

来源：

NANO LETTERS | 2017年 / 17卷 / 03期

基金：

美国国家科学基金会;

关键词：

Cation effect; carrier diffusion; lifetime; time-resolved microwave conductivity; scanning photocurrent microscopy; SOLAR-CELLS; SINGLE-CRYSTALS; CH3NH3PBI3; PEROVSKITE; HYBRID PEROVSKITES; CARRIER LIFETIMES; HIGH-PERFORMANCE; EFFICIENT; DYNAMICS; TRIHALIDE; STATE;

D O I：

10.1021/acs.nanolett.6b05022

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

We use scanning photocurrent microscopy and time-resolved microwave conductivity to measure the diffusion of holes and electrons in a series of lead bromide perovskite single crystals, APbBr(3), with A = methylammonium (MA), formamidinium (FA), and Cs. We find that the diffusion length of holes (L(D)h(+) similar to 10-50 mu m) is on average an order of magnitude longer than that of electrons (LDe- similar to 1-5 mu m), regardless of the A-type cation or applied bias. Furthermore, we observe a weak dependence of L-D across the A-cation series MA > FA > Cs. When considering the role of the halide, we find that the diffusion of holes in MAPbBr(3) is comparable to that in MAPbI(3), but the electron diffusion length is up to five times shorter. This study shows that the disparity between hole and electron diffusion is a ubiquitous feature of lead halide perovskites. As with organic photovoltaics, this imbalance will likely become an important consideration in the optimization of lead halide perovskite solar cells.

引用

页码：1727 / 1732

页数：6

共 38 条

[1] Scanning photocurrent imaging and electronic band studies in silicon nanowire field effect transistors [J].