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Bifunctional hole-shuttle molecule for improved interfacial energy level alignment and defect passivation in perovskite solar cells
Release time:2023-07-31  Hits:

Indexed by: Article

Correspondence Author: Xiong Li

Journal: Nature Energy

Included Journals: SCI

Discipline: Engineering

First-Level Discipline: Other specialties in Optical Engineering

Document Type: J

DOI number: 10.1038/s41560-023-01249-0

Date of Publication: 2023-04-17

Impact Factor: 67.439

Abstract: Perovskite solar cells have reached a power conversion efficiency over 25%, and the engineering of the interface between the perovskite and hole transport layer (HTL) has been crucial to achieve high performance. Here we design a bifunctional molecule CBz-PAI with carbazole-triphenylamine and phenylammonium iodide units to passivate defects at the perovskite/HTL interface. Owing to a favourable energy level alignment with the perovskite, the CBz-PAI acts as a hole shuttle between the perovskite layer and the HTL. This minimizes the difference between the quasi-Fermi level splitting of the perovskite, or ‘internal’ Voc, and the external device Voc, thus reducing voltage losses. As a result, solar cells incorporating CBz-PAI reach a stabilized power conversion efficiency of 24.7% and maintain 92.3% of the initial efficiency after 1,000 h under damp heat test (85 °C and 85% relative humidity) and 94.6% after 1,100 h under maximum power point-tracking conditions.