Publication Date:
2018-09-16
Description:
Materials, Vol. 11, Pages 1736: Effects of a Si-doped InGaN Underlayer on the Optical Properties of InGaN/GaN Quantum Well Structures with Different Numbers of Quantum Wells Materials doi: 10.3390/ma11091736 Authors: George Christian Menno Kappers Fabien Massabuau Colin Humphreys Rachel Oliver Philip Dawson In this paper we report on the optical properties of a series of InGaN polar quantum well structures where the number of wells was 1, 3, 5, 7, 10 and 15 and which were grown with the inclusion of an InGaN Si-doped underlayer. When the number of quantum wells is low then the room temperature internal quantum efficiency can be dominated by thermionic emission from the wells. This can occur because the radiative recombination rate in InGaN polar quantum wells can be low due to the built-in electric field across the quantum well which allows the thermionic emission process to compete effectively at room temperature limiting the internal quantum efficiency. In the structures that we discuss here, the radiative recombination rate is increased due to the effects of the Si-doped underlayer which reduces the electric field across the quantum wells. This results in the effect of thermionic emission being largely eliminated to such an extent that the internal quantum efficiency at room temperature is independent of the number of quantum wells.
Electronic ISSN:
1996-1944
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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