scholarly journals Direct band gap narrowing in highly doped Ge

2013 ◽  
Vol 102 (15) ◽  
pp. 152106 ◽  
Author(s):  
Rodolfo Camacho-Aguilera ◽  
Zhaohong Han ◽  
Yan Cai ◽  
Lionel C. Kimerling ◽  
Jurgen Michel
2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
E. Kasper ◽  
M. Oehme ◽  
T. Arguirov ◽  
J. Werner ◽  
M. Kittler ◽  
...  

Room temperature direct band gap emission is observed for Si-substrate-based Ge p-i-n heterojunction photodiode structures operated under forward bias. Comparisons of electroluminescence with photoluminescence spectra allow separating emission from intrinsic Ge (0.8 eV) and highly doped Ge (0.73 eV). Electroluminescence stems from carrier injection into the intrinsic layer, whereas photoluminescence originates from the highly n-doped top layer because the exciting visible laser wavelength is strongly absorbed in Ge. High doping levels led to an apparent band gap narrowing from carrier-impurity interaction. The emission shifts to higher wavelengths with increasing current level which is explained by device heating. The heterostructure layer sequence and the light emitting device are similar to earlier presented photodetectors. This is an important aspect for monolithic integration of silicon microelectronics and silicon photonics.


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.


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