Significance of third-order elasticity for determination of the pressure coefficient of the light emission in strained quantum wells

2008 ◽  
Vol 78 (15) ◽  
Author(s):  
S. P. Łepkowski

2001 ◽  
Vol 79 (10) ◽  
pp. 1483-1485 ◽  
Author(s):  
S. P. Łepkowski ◽  
H. Teisseyre ◽  
T. Suski ◽  
P. Perlin ◽  
N. Grandjean ◽  
...  


2011 ◽  
Vol 59 (7) ◽  
pp. 2773-2782 ◽  
Author(s):  
Jun-jie Shi ◽  
Shuai Zhang ◽  
Mao Yang ◽  
Shang-guo Zhu ◽  
Min Zhang


2001 ◽  
Vol 188 (2) ◽  
pp. 839-843 ◽  
Author(s):  
P. Perlin ◽  
T. Suski ◽  
S.P. ?epkowski ◽  
H. Teisseyre ◽  
N. Grandjean ◽  
...  




2000 ◽  
Vol 639 ◽  
Author(s):  
P. Perlin ◽  
T. Suski ◽  
P. Wisniewski ◽  
I. Gorczyca ◽  
S. Lepkowski ◽  
...  

ABSTRACTWe have studied an influence of pressure on the emission and absorption spectra measured from various types of InGaN structures such as epilayers, quantum wells and quantum dots. While the known pressure coefficients of GaN and InN bandgaps are in the range 40-25 meV/GPa, the experimental observation for the light emission shift with pressure for InGaN alloys is dramatically different. With the increasing In content and thus decreasing emission energy the observed pressure coefficients become very small eventually reaching zero or even slightly negative values! We have observed a much weaker trend for the decrease of the pressure coefficient for the absorption edges of InGaN. First principle calculations of InGaN band structure and its modification with a pressure are not able to explain the huge effect observed in the emission experiment but are in a good agreement with the results obtained in optical absorption measurements. We discuss here the possible mechanisms which can account for extremely low pressure coefficient of the light emission and the discrepancy between sensitivity light emission and absorption on applied pressure in InGaN alloys.



2004 ◽  
Vol 831 ◽  
Author(s):  
Sławomir P. Łepkowski ◽  
Jacek A. Majewski

ABSTRACTWe have studied the nonlinear elasticity effects in III-N compounds. Particularly, we have determined the pressure dependences of elastic constants in wurtzite and zinc-blende InN, GaN, and AlN by performing ab-initio calculations in the framework of plane-wave pseudopotential implementation of the density-functional theory. We have found that C11, C12 in zinc-blende phase and C11, C12, C13, C33 in wurtzite phase depend significantly and almost linearly on hydrostatic pressure, for all considered nitrides. Much weaker dependences on pressure have been observed for C44 in both wurtzite and zinc-blende phases. Further, we have examined the influence of pressure dependence of elastic constant on the pressure coefficient of light emission, dEE / dP, in wurtzite and cubic, InGaN/GaN and GaN/AlGaN quantum wells. We show that the pressure dependence of elastic constants results in significant reduction of dEE / dP in nitride quantum wells and essentially improves the agreement between experimental and theoretical values.





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