氮化镓外延层中单光子和双光子激发下的载流子复合。

Carrier recombination under one-photon and two-photon excitation in GaN epilayers.

作者信息

Miasojedovas S, Butkus M, Jursenas S, Lucznik B, Grzegory I, Suski T

机构信息

Institute of Material Science and Applied Research, Sauletekio 9, III building, Vilnius LT 10222, Lithuania.

出版信息

Micron. 2009 Jan;40(1):118-21. doi: 10.1016/j.micron.2008.01.011. Epub 2008 Feb 2.

DOI:10.1016/j.micron.2008.01.011

PMID:18316196

Abstract

Luminescence properties of 100-mum thick GaN epilayers grown by hydride vapor phase epitaxy (HVPE) over three different substrates: high-pressure grown n-type bulk GaN (HP-n-GaN), high-pressure bulk GaN doped with magnesium (HP-GaN:Mg), and free-standing HVPE lifted-off from sapphire (FS-HVPE-GaN), were compared by means of one-photon and two-photon excitations. The contribution of carrier capture to nonradiative traps was estimated by the analysis of luminescence transients with carrier diffusion taken into account. The estimated values of carrier lifetime of about 3ns and diffusion coefficient of 1cm(2)/s indicate the highest quality of GaN epilayers on FS-HVPE-GaN substrates.

摘要

通过氢化物气相外延（HVPE）在三种不同衬底上生长的100微米厚GaN外延层的发光特性进行了比较，这三种衬底分别是：高压生长的n型块状GaN（HP-n-GaN）、掺杂镁的高压块状GaN（HP-GaN:Mg）以及从蓝宝石上剥离的自支撑HVPE（FS-HVPE-GaN），采用了单光子和双光子激发手段。通过考虑载流子扩散对发光瞬态进行分析，估算了载流子捕获对非辐射陷阱的贡献。约3纳秒的载流子寿命估算值和1平方厘米/秒的扩散系数表明，FS-HVPE-GaN衬底上的GaN外延层质量最高。