Carrier Dynamics and Optical Function of Nanostructured Nitride Semiconductors

2015 Fiscal Year Final Research Report

• Project/Area Number: 25800180
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics I
• Research Institution: Sophia University
• Principal Investigator: INOSE Yuta 上智大学, 理工学部, 研究員 (90634501)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 窒化物半導体 / キャリアダイナミクス / 量子効率 / 取り出し効率 / 励起子‐フォノン相互作用 / 励起子多体効果 / 誘導放出 / ランダムレージング

Outline of Final Research Achievements

We have researched optical properties of nano-sized nitride columnar semiconductors and demonstrated three items as described below.
(1) Both of internal quantum efficiency and light extraction efficiency of the nano crystals are higher than those of film samples, then nanocolumns show very high external quantum efficiency. (2) We estimated depth of localized states for InGaN/GaN samples, and defined a clear relationship between the depth and the emission efficiency. We measured additionally crystal size dependence of GaN nanocolumns, and we found nano-size effects in the exciton-phonon interaction. (3) We detected stimulated emission via an array of the nano crystals, and observed directly the oscillation mechanism through time-resolved spectroscopy, real spatial images, and wavenumber spatial images. Furthermore, we evinced the influence of structural fluctuation on the column arrays.

Free Research Field

半導体の光物性、ナノ構造による光制御