High‐Efficiency Solution‐Processed Two‐Terminal Hybrid Tandem Solar Cells Using Spectrally Matched Inorganic and Organic Photoactive Materials

Abstract

Although the power conversion efficiency (PCE) of inorganic perovskite‐based solar cells (PSCs) is considerably less than that of organic‐inorganic hybrid PSCs due to their wider bandgap, inorganic perovskites are great candidates for the front cell in tandem devices. Herein, the low‐temperature solution‐processed two‐terminal hybrid tandem solar cell devices based on spectrally matched inorganic perovskite and organic bulk heterojunction (BHJ) are demonstrated. By matching optical properties of front and back cells using CsPbI2Br and PTB7‐Th:IEICO‐4F BHJ as the active materials, a remarkably enhanced stabilized PCE (18.04%) in the hybrid tandem device as compared to that of the single‐junction device (9.20% for CsPbI2Br and 10.45% for PTB7‐Th:IEICO‐4F) is achieved. Notably, the PCE of the hybrid tandem device is thus far the highest PCE among the reported tandem devices based on perovskite and organic material. Moreover, the long‐term stability of inorganic perovskite devices under humid conditions is improved in the hybrid tandem device due to the hydrophobicity of the PTB7‐Th:IEICO‐4F back cell. In addition, the potential promise of this type of hybrid tandem device is calculated, where a PCE of as much as ≈28% is possible by improving the external quantum efficiency and reducing energy loss in the sub‐cells.

Inverted Polymer Solar Cells with Annealing‐Free Solution‐Processable NiO

“…This result was consistent with a previous report (see Table S2, Supporting Information). [ 22 ] The inverted solar cell with the s‐NiO HTL performed comparably to the solar cell with the e‐MoO x HTL, with 11.23% PCE, 23.99 mA cm −2 J SC , 0.719 V V OC , and 65.1% FF. Table 1 lists the measured parameters of photovoltaic performance, and statistics on the photovoltaic parameters are shown in Figure S5 and Table S3, Supporting Information, respectively.…”

Monolithic perovskite/organic tandem solar cells: Developments, prospects, and challenges

“…As summarized in Table 1, so far, only one perovskite/organic tandem device has been reported to have a PCE exceeding 20%, while several devices have PCE exceeding 18%. [ 18,41,42 ] In contrast, many all‐perovskite tandem devices have shown PCE exceeding 20%. [ 16,19,35,43,44 ] As concluded in Table 1 and Table 2, both high‐efficiency perovskite/organic tandem devices (PCE over 18%) and all‐perovskite tandem devices (PCE over 20%) have comparably high FF exceeding 75%.…”

“…Reproduced with permission. [ 42 ] Copyright 2020, Wiley‐VCH. B, Simulated J sc generated in the PM6:Y6‐based tandem cell as a function of thickness of the front and rear cells.…”

All‐Inorganic CsPbI2Br Perovskite Solar Cells: Recent Developments and Challenges

“…Previously, a combination of inorganic CsPbI 2 Br as the front cell and organic PTB7‐Th: COi8DFIC:PC71BM as back cell was successfully developed for the two‐terminal tandem solar device, achieving a promising efficiency of 15.04%. [ 129,130 ] Recently, this strategy was developed by Jang's group, [ 131 ] using a spectrally matched combination of the organic bulk heterojunction with a bandgap of 1.25 eV and a wide‐bandgap inorganic CsPbI 2 Br perovskite. Owing to a near‐optimal absorption spectral match between the front and back cells, an incredible enhancement in device efficiency (18.04%) was achieved for the hybrid tandem device, which is much higher than 9.21% and 10.45% for the single‐junction device.…”