Disclosing exciton binding energy of organic materials from absorption spectrum

Xiong，Chunhua1,2; Sun，Jiuxun2; Cai，Chao2; Caiyang，Weinan2; Zhu，Yuanmin3

2020-07-01

10.1016/j.solener.2020.04.070

SOLAR ENERGY   影响因子和分区

0038-092X

The photoelectric conversion efficiency of organic materials is limited by the exciton splitting at the organic interface which is determined by the exciton binding energy (E). However, E is controversial and hard to directly measure by current methods. We propose a dispersion relation to establish a model to accurately extract E from absorption spectrum. We synthesize an organic-inorganic hybrid perovskite crystal (CHNHPbI) and use the absorption spectrum to verify the method. The result of E is 15 meV at room temperature, which is smaller than 26 meV (thermal energy), implying that our model is not affected by the hot carrier effects. Moreover, this model is applicable to various organic materials (18 kinds). Especially, the binding energy of perovskite is 5 meV under 2 K, which is the same as the result estimated experimentally under 50 Tesla condition. Furthermore, this model allows estimating the effective mass, dielectric constant and excition radius. This work will allow a better understanding of the optoelectronic properties at the interface of organic materials.

Dispersion relation Perovskites Photoelectric properties Solar energy Surficial and interfacial properties

SCI ; EI

英语

其他

National Natural Science Foundation of China[31470822][61703292]

Energy & Fuels

Energy & Fuels

WOS:000537071700014

PERGAMON-ELSEVIER SCIENCE LTD

20201808594497

Absorption spectroscopy ; Photoelectricity ; Solar energy ; Semiconductor quantum wells ; Binding energy ; Interfaces (materials) ; organic-inorganic materials ; Excitons ; Dispersions ; Quantum theory

Minerals:482.2 ; Solar Energy and Phenomena:657.1 ; Electricity: Basic Concepts and Phenomena:701.1 ; Semiconductor Devices and Integrated Circuits:714.2 ; Light/Optics:741.1 ; Physical Chemistry:801.4 ; Quantum Theory; Quantum Mechanics:931.4 ; Materials Science:951

ENGINEERING

2-s2.0-85083901687

Scopus

1.College of Air Traffic Management,Civil Aviation Flight University of China,Guanghan,618307,China
2.School of Physics,University of Electronic Science and Technology of China,Chengdu,610054,China
3.Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology,Shenzhen,518055,China

Xiong，Chunhua,Sun，Jiuxun,Cai，Chao,et al. Disclosing exciton binding energy of organic materials from absorption spectrum[J]. SOLAR ENERGY,2020,204:155-160.

Xiong，Chunhua,Sun，Jiuxun,Cai，Chao,Caiyang，Weinan,&Zhu，Yuanmin.(2020).Disclosing exciton binding energy of organic materials from absorption spectrum.SOLAR ENERGY,204,155-160.

Xiong，Chunhua,et al."Disclosing exciton binding energy of organic materials from absorption spectrum".SOLAR ENERGY 204(2020):155-160.