TY - JOUR
T1 - Defect Passivation by a Donor–Acceptor–Donor-Structured Small Molecule via Bidentate Anchoring for Efficient and Stable Perovskite Solar Cells
AU - Sandhu, Sanjay
AU - Yadagiri, Bommaramoni
AU - Muthu, Senthilkumar
AU - Kaliamurthy, Ashok Kumar
AU - Park, Jongdeok
AU - Kang, Hyeong Cheol
AU - Ryu, Junyeong
AU - Lee, Jae Joon
N1 - Publisher Copyright:
© 2022 Wiley-VCH GmbH.
PY - 2022/12
Y1 - 2022/12
N2 - Perovskite solar cells (PSCs) have exhibited a tremendous photovoltaic performance over the past few years. However, the ionic nature of perovskite and the solution-processable fabrication methods lead to various defects (vacancies, interstitials, and antisites) at the perovskite surface. Incorporating interfacial or surface passivation layers has proved to be crucial in passivating these defects. Herein, a novel donor–acceptor–donor (D–A–D)-based bidentate material, namely, BDTBT, consisting of benzothiadiazole (BDT) as the central acceptor unit and benzothiophene (BT) as a donor end cap unit, is synthesized. The various structural analyses reveal that N and S heteroatoms at BDTBT coordinate effectively to undercoordinated Pb2+ in perovskite via Pb–N/S bidentate interactions. As a result, the BDTBT-treated perovskite exhibits an improved power conversion efficiency (PCE) of 20.42% compared with the bare perovskite, having a PCE of 17.18%. The BDTBT incorporation provides favorable band alignment, increased hole transfer, and suppressed nonradiative recombination losses by reducing the surface defect states. In addition, there is significant increase in the device stability and moisture resistance owing to the hydrophobic nature of BDTBT. This study provides a simple and efficient route to obtain stable and highly efficient PSCs by incorporating small molecules as an additional interfacial layer.
AB - Perovskite solar cells (PSCs) have exhibited a tremendous photovoltaic performance over the past few years. However, the ionic nature of perovskite and the solution-processable fabrication methods lead to various defects (vacancies, interstitials, and antisites) at the perovskite surface. Incorporating interfacial or surface passivation layers has proved to be crucial in passivating these defects. Herein, a novel donor–acceptor–donor (D–A–D)-based bidentate material, namely, BDTBT, consisting of benzothiadiazole (BDT) as the central acceptor unit and benzothiophene (BT) as a donor end cap unit, is synthesized. The various structural analyses reveal that N and S heteroatoms at BDTBT coordinate effectively to undercoordinated Pb2+ in perovskite via Pb–N/S bidentate interactions. As a result, the BDTBT-treated perovskite exhibits an improved power conversion efficiency (PCE) of 20.42% compared with the bare perovskite, having a PCE of 17.18%. The BDTBT incorporation provides favorable band alignment, increased hole transfer, and suppressed nonradiative recombination losses by reducing the surface defect states. In addition, there is significant increase in the device stability and moisture resistance owing to the hydrophobic nature of BDTBT. This study provides a simple and efficient route to obtain stable and highly efficient PSCs by incorporating small molecules as an additional interfacial layer.
KW - bidentate anchoring
KW - defect passivations
KW - donor–acceptor–donors
KW - perovskite solar cells
KW - small molecules
UR - http://www.scopus.com/inward/record.url?scp=85138991467&partnerID=8YFLogxK
U2 - 10.1002/solr.202200786
DO - 10.1002/solr.202200786
M3 - Article
AN - SCOPUS:85138991467
SN - 2367-198X
VL - 6
JO - Solar RRL
JF - Solar RRL
IS - 12
M1 - 2200786
ER -