Depth-dependent porous silicon photoluminescence
- 15 November 1993
- journal article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 74 (10) , 6375-6382
- https://doi.org/10.1063/1.355162
Abstract
Porous silicon showing a two-layer structure is studied by stepwise peeling the surface layer to clarify the nonuniformity in photoluminescence (PL) emission as a function of depth. The upper layer is amorphous and luminesces at higher energy and efficiency. The deeper the depth or the lower the excitation energy Eex, the lower the PL peak Ep; but, at a low Eex, Ep is not sensitive to the depth. Both intrinsic PL emission and the variation of penetration depth with Eex contribute to the linear dependence of Ep on Eex, which is in contrast to the cases of a-Si:H and siloxene exhibiting thermalization gaps. The total PL excitation spectrum, the integrated PL intensities versus Eex, saturates rather than exhibiting a peak. Its leading edge profile is similar to that for the absorption spectrum, unchanged by the depth, and described by an Urbach tail with energy of 0.26 eV, which is 4–5 times larger than that of a-Si:H. The results can be understood based on silicon clusters embedded in amorphous silicon incorporating oxygen and/or hydrogen.This publication has 33 references indexed in Scilit:
- Rapid-thermal-oxidized porous Si−The superior photoluminescent SiApplied Physics Letters, 1992
- Direct evidence for the amorphous silicon phase in visible photoluminescent porous siliconApplied Physics Letters, 1992
- Microluminescence depth profiles and annealing effects in porous siliconApplied Physics Letters, 1992
- Correlation between silicon hydride species and the photoluminescence intensity of porous siliconApplied Physics Letters, 1992
- Study of Luminescent Region in Anodized Porous Silicons by Photoluminescence Imaging and Their MicrostructuresJapanese Journal of Applied Physics, 1992
- Electronic structure of light-emitting porous SiApplied Physics Letters, 1992
- The origin of visible luminescencefrom “porous silicon”: A new interpretationSolid State Communications, 1992
- Correlation of Raman and photoluminescence spectra of porous siliconApplied Physics Letters, 1992
- Visible light emission due to quantum size effects in highly porous crystalline siliconNature, 1991
- Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafersApplied Physics Letters, 1990