In:
Advanced Functional Materials, Wiley, Vol. 30, No. 27 ( 2020-07)
Abstract:
In perovskite solar cells (PSCs), the interfaces of the halide perovskite/electron transport layer (ETL) and ETL/metal oxide electrode (MOE) always attract and trap free carriers via the surface electrostatic force, altering quasi‐Fermi level ( E Fq ) splitting of contact interfaces, and significantly limit the charge extraction efficiency and intrinsic stability of devices. Herein, a graded “bridge” is first reported to link the MOE and perovskite interfaces by self vertical phase separation doping (PSD), diminishing the side effect of notorious ionic defects via both reinforced interface E bi and the vacancies filling. Experimental and theoretical results prove that the inhomogeneous distribution of CsF in the bulk or surface of PC 61 BM would not only form metal–oxygen (M–O) dipole on MOE, reinforcing the interface E bi , but also create a graded energy bridge to alleviate the disadvantage of band offset raised by the enhanced interface E bi , which significantly avoid the carrier accumulation and recombination at defective interfaces. Employing PSD, the power conversion efficiency of the devices approaches 21% with a high open‐circuit voltage (1.148 V) and delivers a high stability of 89% after aging 60 days in atmosphere without encapsulation, which is the highest efficiency of organic electron transport layers for n–i–p PSCs.
Type of Medium:
Online Resource
ISSN:
1616-301X
,
1616-3028
DOI:
10.1002/adfm.202001418
Language:
English
Publisher:
Wiley
Publication Date:
2020
detail.hit.zdb_id:
2029061-5
detail.hit.zdb_id:
2039420-2
SSG:
11