LI XIONG

Paper Publications

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.