Stable porous crystalline silicon with nanotubular structure: A predicted allotrope with direct band gap

2015 ◽  
Vol 466-467 ◽  
pp. 59-63 ◽  
Author(s):  
Chi-Pui Tang ◽  
Jie Cao ◽  
Shi-Jie Xiong
Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2006 ◽  
Author(s):  
Murugesan Rasukkannu ◽  
Dhayalan Velauthapillai ◽  
Federico Bianchini ◽  
Ponniah Vajeeston

Due to the low absorption coefficients of crystalline silicon-based solar cells, researchers have focused on non-silicon semiconductors with direct band gaps for the development of novel photovoltaic devices. In this study, we use density functional theory to model the electronic structure of a large database of candidates to identify materials with ideal properties for photovoltaic applications. The first screening is operated at the GGA level to select only materials with a sufficiently small direct band gap. We extracted twenty-seven candidates from an initial population of thousands, exhibiting GGA band gap in the range 0.5–1 eV. More accurate calculations using a hybrid functional were performed on this subset. Based on this, we present a detailed first-principle investigation of the four optimal compounds, namely, TlBiS2, Ba3BiN, Ag2BaS2, and ZrSO. The direct band gap of these materials is between 1.1 and 2.26 eV. In the visible region, the absorption peaks that appear in the optical spectra for these compounds indicate high absorption intensity. Furthermore, we have investigated the structural and mechanical stability of these compounds and calculated electron effective masses. Based on in-depth analysis, we have identified TlBiS2, Ba3BiN, Ag2BaS2, and ZrSO as very promising candidates for photovoltaic applications.


2013 ◽  
Vol 652-654 ◽  
pp. 527-531 ◽  
Author(s):  
A.N. Alias ◽  
T.I. Tunku Kudin ◽  
Z.M. Zabidi ◽  
M.K. Harun ◽  
Ab Malik Marwan Ali ◽  
...  

The optical absorption spectra of blended poly (N-carbazole) (PVK) with polyvinylpyrrolidone (PVP) in various compositions are investigated. A doctor blade technique was used to coat the blended polymer on a quartz substrate. The electronic parameters such as absorption edge (Ee), allowed direct band gap (Ed), allowed indirect band gap (Ei), Urbach edge (Eu) and steepness parameter (γ) were calculated using Tauc/Davis-Mott Model. The results reveal that the Ee, Ed and Ei increase with increasing of PVP ratio. There also have variation changing in Urbach energy and steepness parameter.


2014 ◽  
Vol 44 (1) ◽  
pp. 167-176 ◽  
Author(s):  
Adit Ghosh ◽  
Chandrika Varadachari
Keyword(s):  
Band Gap ◽  

2015 ◽  
Vol 54 (10) ◽  
pp. 3112-3115 ◽  
Author(s):  
Shengli Zhang ◽  
Zhong Yan ◽  
Yafei Li ◽  
Zhongfang Chen ◽  
Haibo Zeng
Keyword(s):  
Band Gap ◽  

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.


2014 ◽  
Vol 104 (3) ◽  
pp. 031106 ◽  
Author(s):  
Masahiro Matsue ◽  
Yuhsuke Yasutake ◽  
Susumu Fukatsu ◽  
Takuji Hosoi ◽  
Takayoshi Shimura ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document