High-Efficiency Semitransparent Organic Photovoltaics Containing Vertical Multiheterojunctions

作者：Bin Chang, Yu‐Che Lin, Shaun Tan, Chung‐Hao Chen, Hao‐Wen Cheng, Yepin Zhao, Haocheng Wang, Qiyu Xing, Li‐Yin Chen, Chung‐An Hsieh, Chang-Yu Hsiao, Yang Yang, Kung‐Hwa Wei · 发表于：ACS Applied Energy Materials · 年份：2022 · DOI：10.1021/acsaem.2c02416 · 被引用次数：23 · 研究领域：Organic Electronics and Photovoltaics、Conducting polymers and applications、Organic Light-Emitting Diodes Research

Although semitransparent organic photovoltaics (ST-OPVs) are attractive components of various building-integrated photovoltaic applications, there is an intrinsic trade-off in their power conversion efficiencies (PCEs) and average visible transmissions (AVTs)─because the photocurrent generated usually requires substantial absorption in the visible light that determines transmission. In this paper, we describe a vertically stacked tunable multiheterojunction strategy toward highly efficient ST-OPVs that simultaneously maintain high AVTs. The vertical triheterojunctions of the active layer comprise one polymer donor, D18, and two small molecule acceptors, Y1 and Y6, that were formed with a sequentially deposited (SD) method. The triheterojunction structures not only introduced cascading energy levels of their lowest unoccupied molecular energy levels that aligned in parallel to the charge extraction direction but also can be tuned by varying their relative thicknesses, thereby significantly improving charge transport in the ST-OPVs without severely suffering AVT losses. We demonstrate the universality and broad tunability of this technique for balancing the PCEs and AVTs of the devices. Our ST-OPVs achieved champion PCEs as high as 13.9% at an AVT of 22.8% (100 nm active layer with deposited trilayers having D18, Y1, and Y6 at 45, 5, and 50 nm, respectively) and 13.5% at an AVT of 23.8% (100 nm active layer with deposited trilayers having D18, Y1, and Y6 at 40, 10, and 50 nm, r...