Enhancement of photoluminescence by microdisk formation from Si/Ge/Si single quantum wells

Abstract

Anisotropic strain effects on the photoluminescence emission from heteroepitaxial and homoepitaxial nonpolar (Zn,Mg)O/ZnO quantum wells

Fabrication and Photoluminescence Study of Large-Area Ordered and Size-Controlled GeSi Multi-quantum-well Nanopillar Arrays

“…To further improve the quantum efficiency of Si/Ge heterostructures, different surface microstructures have also been proposed. The Choi group [ 12 ] observed a huge enhancement in the photoluminescence (PL) spectra from microdisk arrays of Si/Ge/Si SQW and proposed several mechanisms for the enhancement. One is the localization of excitons, which are spatially confined by the diameter of the microdisk.…”

Uniform SiGe/Si quantum well nanorod and nanodot arrays fabricated using nanosphere lithography

“…A significant enhancement of the quantum efficiency in the PL spectra has been observed by forming GaN/AlGaN MQW microdisks of about 9-μm diameter and interpreted as a suppression of impurity-related transitions [38]. Choi et al also associated the PL enhancement with carrier localization in the 500- and 1,000-nm-diameter Si/Ge/Si microdisks fabricated by electron beam lithography, the existence of which suppresses impurity-related nonradiative combination [9]. The similar mechanism may also contribute to the enhancement of PL intensity in our SiGe/Si MQW nanorod arrays.…”

“…The well-known top-down techniques providing accurate size and geometric control in periodic semiconductor nanostructure patterning include laser interference lithography [6], nanoimprint lithography [7], ion beam lithography [8], and electron beam lithography [9]. However, the cost and complexity of these techniques increase dramatically with the demand for reduced feature sizes over large areas.…”

“…For this purpose, Si/Ge superlattices (SLs) [21], multiple quantum wells (MQWs) [22], and multiple quantum dots (MQDs) [23] have been demonstrated to adjust the bandgap and reduce nonradiative recombination. Choi et al further reported that the formation of microdisks from the Si/Ge/Si single QW using electron beam lithography significantly enhanced the intrinsic photoluminescence (PL) transitions [9]. Chen also fabricated pyramidal nanodots that possess Si/Ge SLs by chemical selective etching through a self-assembled Ge QD nanomask and found an obvious enhancement in PL emission [24].…”

A luminescence enhancement approach through Si/O nanostructure

“…Several approaches to enhance luminescence have been developed in two ways: one is to increase the radiative recombination rate of excitons, the second is to reduce the number of non-radiative recombination paths. Most efforts have focused on the quantum confinement effect of silicon nanocrystals [2][3][4][5] or dislocation loops [6,7] , which lead to a direct band transition. Emission center addition like Er doping offers another road to emission enhancement [8,9] .…”