[15a-A302-1~12] 15.4 III-V族窒化物結晶

▼ [15a-A302-5] InGaN quantum wells with spatially engineered indium content for broadening of nitride superluminescent diode emission spectra

〇Anna Kafar^1,2、Ryota Ishii¹、Krzysztof Gibasiewicz²、Szymon Stanczyk²、Szymon Grzanka^2,3、Mikiya Tano⁴、Atsushi Sakaki⁴、Tadeusz Suski²、Piotr Perlin^2,3、Mitsuru Funato¹、Yoichi Kawakami¹ (1.Kyoto Univ.、2.IHPP PAS、3.TopGaN Ltd.、4.Nichia Corp.)

キーワード：InGaN, substrate misorientation, photoluminescence

Nitride superluminescent diodes combine high spatial coherence and low temporal coherence of emitted light, which makes them promising lights sources for applications such as optical coherence tomography - requiring a broadband light source. In this work, we present InGaN quantum wells with spatially modified indium content that can be used as active region of SLDs to broaden their emission spectrum. Within this work, we modified the local misorientation angle of a bulk GaN substrate by etching 3D patterns. This influenced the indium incorporation during the epitaxial growth and lead to obtaining blue-violet InGaN quantum wells with spatial variation of emission wavelength. Micro photoluminescence study of the sample showed a smooth emission shift of up to 35 nm, depending on the excitation level. The Energy Dispersive X-Ray analysis with scanning transmission electron microscopy proved that local indium content correlates with the emission wavelength. Various surface pattern shapes were examined and their emission energy distribution suggests similar indium incorporation mechanism for a- and m-direction.