Constructing High‐Performance Solar Cells and Photodetectors with a Doping‐Free Polythiophene Hole Transport Material.

The emerging solution‐based solar cells and photodetectors have gained worldwide research interest over the past decades. Hole transport materials (HTMs) have greatly advanced the progress of these solution‐based electronics. Nevertheless, developing low‐cost and efficient HTMs is far from satisfactory. In this contribution, poly(3‐pentylthiophene) (P3PT) is introduced as a facile, low‐cost, and versatile dopant‐free polymer HTM for both quantum dot (QD) and perovskite electronic devices. Compared to the broadly used poly(3‐hexylthiophene), P3PT presents the reduced molecular aggregation and preferential face‐on orientation, which can markedly enhance the hole‐carrier transport in optoelectronic devices. Accordingly, P3PT can deliver the substantial improvement of photovoltaic performance from ∼8.6% to ∼9.5% for QD/polythiophene solar cells and from ∼16% to ∼18.8% for perovskite/polythiophene solar cells, which are both among the topmost values in the corresponding fields. Furthermore, P3PT HTMs can also significantly enhance the photodetection performance of QD and perovskite photodetectors by a factor of ∼3, indicating its great application potential in a variety of emerging optoelectronics. [ABSTRACT FROM AUTHOR]