TY - JOUR
T1 - Unraveling Urbach Tail Effects in High-Performance Organic Photovoltaics
T2 - Dynamic vs Static Disorder
AU - Zhang, Chujun
AU - Mahadevan, Sudhi
AU - Yuan, Jun
AU - Ho, Johnny Ka Wai
AU - Gao, Yaxin
AU - Liu, Wei
AU - Zhong, Hui
AU - Yan, He
AU - Zou, Yingping
AU - Tsang, Sai Wing
AU - So, Shu Kong
N1 - Funding Information:
S.K.S. acknowledges support from the Research Grant Council of Hong Kong under Collaborative Research Grant C6023-196F. S.-W.T. acknowledges support from the Research Grant Council of Hong Kong (Grant #11303618). Y.Z. acknowledges support from the National Natural Science Foundation of China (52125306). J.Y. acknowledges support from the National Natural Science Foundation of China (22005374).
Publisher Copyright:
© 2022 The Authors. Published by American Chemical Society.
PY - 2022/6/10
Y1 - 2022/6/10
N2 - The origin of Urbach energy (EU) in organic semiconductors and its effect on photovoltaic properties remain a topic of intense interest. In this letter, we demonstrate quantitative information on the EU value in emerging Y-series molecules by an in-depth analysis of the line shape of the temperature-dependent quantum efficiency spectra. We found that the static disorder (EU(0)), which is dominated by the conformational uniformity in Y-series acceptors, contributes 10–25 meV to the total Urbach energy. Particularly, this static contribution in organic solar cells (OSCs) is much higher than those (EU(0) ≈ 3–6 meV) in inorganic/hybrid counterparts, such as CH3NH3PbI3 perovskite, crystalline silicon (c-Si), gallium nitride (GaN), indium phosphide (InP), and gallium arsenide (GaAs). More importantly, we establish clear correlations between the static disorder and photovoltaic performance and open-circuit voltage loss. These results suggest that suppressing the static disorder via rational molecular design is clearly a path for achieving higher performance.
AB - The origin of Urbach energy (EU) in organic semiconductors and its effect on photovoltaic properties remain a topic of intense interest. In this letter, we demonstrate quantitative information on the EU value in emerging Y-series molecules by an in-depth analysis of the line shape of the temperature-dependent quantum efficiency spectra. We found that the static disorder (EU(0)), which is dominated by the conformational uniformity in Y-series acceptors, contributes 10–25 meV to the total Urbach energy. Particularly, this static contribution in organic solar cells (OSCs) is much higher than those (EU(0) ≈ 3–6 meV) in inorganic/hybrid counterparts, such as CH3NH3PbI3 perovskite, crystalline silicon (c-Si), gallium nitride (GaN), indium phosphide (InP), and gallium arsenide (GaAs). More importantly, we establish clear correlations between the static disorder and photovoltaic performance and open-circuit voltage loss. These results suggest that suppressing the static disorder via rational molecular design is clearly a path for achieving higher performance.
UR - http://www.scopus.com/inward/record.url?scp=85131140898&partnerID=8YFLogxK
U2 - 10.1021/acsenergylett.2c00816
DO - 10.1021/acsenergylett.2c00816
M3 - Journal article
SN - 2380-8195
VL - 7
SP - 1971
EP - 1979
JO - ACS Energy Letters
JF - ACS Energy Letters
IS - 6
ER -
