Bias-dependent Photoabsorption Properties of GaN Porous Structures under Back-side Illumination
Bias-dependent Photoabsorption Properties of GaN Porous Structures under Back-side Illumination
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背面照明下 GaN 多孔结构的偏压相关光吸收特性
DOI：
10.1149/06902.0161ecst
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
and Z. Yatabe
中科院分区：
文献类型：
--
作者：
T. Sato;H. Kida;Y. Kumazaki;and Z. Yatabe
通过测量GaN多孔结构在不同波长单色光下的光电流和光透过率，研究了GaN多孔结构的光吸收特性。在多孔GaN电极上测得的光电流大于平面电极上的光电流，即使在光子能量低于体相GaN带隙能量的情况下也能观察到这些光电流。此外，在背面照明(BSI)模式下测量的光透过率强烈依赖于施加到多孔电极的电压随光电流的变化。观察到的光吸收性质可以用Franz-Keldysh效应定性地解释，即GaN多孔结构中产生的高电场容易引起光吸收边的红移。
Photoabsorption properties of GaN porous structures were investigated by measuring photocurrent and light transmittance under monochromatic light with various wavelengths. The measured photocurrents on the porous GaN electrode were larger than those on the planar electrodes, and those were observed even under illumination with lower photon energy than the bandgap energy of bulk GaN. Moreover, the light transmittance that was measured in the back-side illumination (BSI) mode depended strongly on the applied voltage to the porous electrode with change of the photocurrents. The observed photoabsorption properties can be qualitatively explained by the Franz-Keldysh effect; namely, the high electric field induced in the GaN porous structure easily causes a redshift of the photoabsorption edge.