Long-Range Carrier Diffusion in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mo stretchy="false">(</mml:mo><mml:mi>In</mml:mi><mml:mo>,</mml:mo><mml:mi>Ga</mml:mi><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mrow><mml:mi mathvariant="normal">N</mml:mi></mml:mrow></mml:mrow></mml:math> Quantum Wells and Implications from Fundamentals to Devices

Abstract

Photoluminescence measurements on high-quality $(\mathrm{In},\mathrm{Ga})\mathrm{N}$ quantum wells reveal that carriers diffuse laterally to long distances at room temperature, up to tens of microns. This behavior, which shows a pronounced dependence on the excitation density, contrasts with the common expectation of a short diffusion length. The data is well explained by a diffusion model taking into account the full carrier recombination dynamics, obtained from time-resolved measurements. These observations have important implications for understanding the high efficiency of III-nitride emitters, but also for proper interpretation of photoluminescence experiments and for the design of efficient small-scale devices.

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