A two-dimensional GeSe/SnSe heterostructure for high performance thin-film solar cells

2019 ◽  
Vol 7 (18) ◽  
pp. 11265-11271 ◽  
Author(s):  
Yuliang Mao ◽  
Congsheng Xu ◽  
Jianmei Yuan ◽  
Hongquan Zhao

Based on first-principles calculations, we demonstrated that a GeSe/SnSe heterostructure has a type-II band alignment and a direct band gap. The predicted photoelectric conversion efficiency (PCE) for the GeSe/SnSe heterostructure reaches 21.47%.

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1565
Author(s):  
Yuliang Mao ◽  
Zheng Guo ◽  
Jianmei Yuan ◽  
Tao Sun

Based on first-principles calculations, we propose van der Waals (vdW) heterojunctions composed of one-dimensional carbon nanotubes (CNTs) and two-dimensional GeSe. Our calculations show that (n,0)CNT/GeSe (n = 5–11) heterojunctions are stable through weak vdW interactions. Among these heterojunctions, (n,0)CNT/GeSe (n = 5–7) exhibit metallic properties, while (n,0)CNT/GeSe (n = 8–11) have a small bandgap, lower than 0.8 eV. The absorption coefficient of (n,0)CNT/GeSe (n = 8–11) in the ultraviolet and infrared regions is around 105 cm−1. Specifically, we found that (11,0)CNT/GeSe exhibits type-II band alignment and has a high photoelectric conversion efficiency of 17.29%, which suggests prospective applications in photoelectronics.


RSC Advances ◽  
2015 ◽  
Vol 5 (102) ◽  
pp. 83876-83879 ◽  
Author(s):  
Chengyong Xu ◽  
Paul A. Brown ◽  
Kevin L. Shuford

We have investigated the effect of uniform plane strain on the electronic properties of monolayer 1T-TiS2using first-principles calculations. With the appropriate tensile strain, the material properties can be transformed from a semimetal to a direct band gap semiconductor.


RSC Advances ◽  
2016 ◽  
Vol 6 (98) ◽  
pp. 95846-95854 ◽  
Author(s):  
Wencheng Tang ◽  
Minglei Sun ◽  
Qingqiang Ren ◽  
Yajun Zhang ◽  
Sake Wang ◽  
...  

Using first principles calculations, we predicted that a direct-band-gap between 0.98 and 2.13 eV can be obtained in silicene by symmetrically and asymmetrically (Janus) functionalisation with halogen atoms and applying elastic tensile strain.


2019 ◽  
Vol 7 (12) ◽  
pp. 3569-3575 ◽  
Author(s):  
Shifeng Qian ◽  
Xiaowei Sheng ◽  
Xian Xu ◽  
Yuxiang Wu ◽  
Ning Lu ◽  
...  

Two-dimensional binary MX2 (M = Ni, Pd and Pt; X = P and As) exhibiting a beautiful pentagonal ring network is discussed through first principles calculations.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Gang Xu ◽  
Hao Lei

The electronic structure of GaSe/silicane (GaSe/SiH) van der Waals (vdW) heterostructure in response to a vertical electric field and strain was studied via first-principle calculations. The heterostructure had indirect band gap characteristics in the range [−1.0, −0.4] V/Å and direct band gap features in the range [−0.3, 0.2] V/Å. Furthermore, a type-II to type-I band alignment transition appeared at −0.7 and −0.3 V/Å. Additionally, the GaSe/SiH vdW heterostructure had a type-II band alignment under strain, but an indirect to direct band gap semiconductor transition occurred at −3%. These results indicated that the GaSe/SiH vdW heterostructure may have applications in novel nanoelectronic and optoelectronic devices.


2016 ◽  
Vol 30 (03) ◽  
pp. 1650007
Author(s):  
Naeemullah ◽  
G. Murtaza ◽  
R. Khenata ◽  
S. Bin Omran

For the first time, the electronic and optical properties of the quaternary Be[Formula: see text]Mg[Formula: see text]Zn[Formula: see text]Se alloy have been investigated using first-principles calculations within the framework of density functional theory (DFT). Variations in the direct band gap with the change in [Formula: see text] and [Formula: see text] compositions show agreement with the experimental measurements. Evaluation of the dielectric function and refractive index reveals the optical activity in the visible and ultraviolet energy regions.


2017 ◽  
Vol 31 (18) ◽  
pp. 1750201 ◽  
Author(s):  
Ruike Yang ◽  
Chuanshuai Zhu ◽  
Qun Wei ◽  
Zheng Du

Two novel aluminum nitride (which is bct-AlN at ambient pressure, and h-AlN at higher pressure) were predicted using first-principles calculations. The mechanical and phonon dispersion results indicate that bct-AlN is mechanically and dynamically stable at zero pressure, h-AlN phase can be stabilized by increasing pressure and it is mechanically and dynamically stable at 10 GPa. bct-AlN is more favorable than rs-AlN in thermodynamics at ambient pressure. Our calculated band gap of bct-AlN is 5.85 eV. It can be used as semiconductor device and optoelectronic device due to its inherent wide direct band gap. For bct-AlN, the shortest Al–N bond length is 1.8476 Å and its bond order index is 1.28, which shows that strong covalent bonds are formed between Al atoms and N atoms. Moreover, the anisotropy of Young’s modulus and optical properties can be noticed obviously for bct-AlN.


2020 ◽  
Vol 22 (36) ◽  
pp. 20712-20720
Author(s):  
Zhu Wang ◽  
Fangwen Sun ◽  
Jian Liu ◽  
Ye Tian ◽  
Zhihui Zhang ◽  
...  

The InSb/InSe heterostructure with tunable electronic properties has a direct band gap and an intrinsic type-II band alignment.


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