2019

Tellurium-Based Double Perovskites A2TeX6 with Tunable Band Gap and Long Carrier Diffusion Length for Optoelectronic Applications

Tellurium-Based Double Perovskites A2TeX6 with Tunable Band Gap and Long Carrier Diffusion Length for Optoelectronic Applications
Dianxing Ju, Xiaopeng Zheng, Jun Yin, Zhiwen Qiu, Bekir Türedi, Xiaolong Liu, Yangyang Dang, Bingqiang Cao, Omar F. Mohammed, Osman M. Bakr, Xutang Tao
ACS Energy Lett., 2019, 4 (1), pp 228–234
Dianxing Ju, Xiaopeng Zheng, Jun Yin, Zhiwen Qiu, Bekir Türedi, Xiaolong Liu, Yangyang Dang, Bingqiang Cao, Omar F. Mohammed, Osman M. Bakr, Xutang Tao
Tunable Band Gap, Long Carrier Diffusion Length
2019
​Lead-free hybrid perovskites have attracted immense interest as environmentally friendly light absorbers. Here, we report on tellurium (Te)-based double perovskites A2TeX6 (A = MA, FA, or BA; X = Br– or I–; MA = CH3NH3; FA = CH(NH2)2; BA = benzylamine) as potentially active materials for optoelectronic devices. These perovskites exhibit a tunable band gap (1.42–2.02 eV), a low trap density (∼1010 cm–3), and a high mobility (∼65 cm2 V–1 s–1). Encouragingly, the MA2TeBr6 single crystal with a band gap of 2.00 eV possesses a long carrier lifetime of ∼6 μs and corresponding carrier diffusion lengths of ∼38 μm, which are ideal characteristics for a material for photodetectors and tandem solar cells. Moreover, A2TeX6 perovskites are relatively robust in ambient conditions, being stable for at least two months without showing any signs of phase change. Our findings bring to the forefront a family of lead-free Te-based perovskites for nontoxic perovskite optoelectronics.
DOI: 10.1021/acsenergylett.8b02113