Controlling Crystallization of Quasi‐2D Perovskite Solar Cells: Incorporating Bulky Conjugated Ligands
Abstract
Quasi‐2D hybrid halide perovskites have drawn considerable attention due to their improved stability and facile tunability compared to 3D perovskites. The expansiveness of possibilities has thus far been limited by the difficulty in incorporating large ligands into thin‐film devices. Here, a bulky bi‐thiophene 2T ligand is focused on to develop a solvent system around creating strongly vertically‐aligned (2T)2(MA)6Pb7I22 (n = 7) quasi‐2D perovskite films. By starting with a poorly coordinating solvent (gamma‐butyrolactone) and adding a small amount of dimethylsulfoxide and methanol, it is found that vertical orientation and z‐uniformity is greatly improved. These are carefully examined and verified using grazing‐incidence wide‐angle X‐ray scattering analysis and advanced optical characterizations. These films are incorporated into champion solar cells that achieve a power conversion efficiency of 13.3%, with a short‐circuit current density of 18.9 mA cm‐2, an open‐circuit voltage of 0.96 V, and a fill factor of 73.8%. Furthermore, the quasi‐2D absorbing layers show excellent stability in moisture, remaining unchanged after hundreds of hours. In addition, 2T is compared with the more common ligands butylammonium and phenylethylammonium in this solvent system to develop heuristics and deeper understanding of how to incorporate large ligands into stable photovoltaic devices.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 03, 2022
- Source ID
- 10.1002/aenm.202201501
Entities
People
- Aidan H. Coffey
- Blake P Finkenauer
- Chenhui Zhu
- Letian Dou
- Martín Gómez-Dominguez
- Seok Joo Yang
- Tanguy Terlier
Organizations
- Advanced Light Source
- National Science Foundation
- Purdue University
- Rice University