InGaAs/InAlAs 양자우물구조의 발광특성에 대한 In_(0.4)Al_(0.6)As 버퍼층 성장온도의 영향 (Growth Temperature Effects of In_(0.4)Al_(0.6)As Buffer Layer on the Luminescence Properties of InGaAs/InAlAs Quantum Well Structures)

서지정보

· 발행기관 : 한국진공학회
· 수록지 정보 : Applied Science and Convergence Technology / 20권 / 6호 / 449 ~ 455페이지
· 저자명 : 김희연, 류미이, 임주영, 신상훈, 김수연, 송진동

초록

In0.4Al0.6As 버퍼층의 성장온도 변화에 따른 In_(0.5)Ga_(0.5)As/In_(0.5)Al_(0.5)As 다중양자우물(multiple quantum wells, MQWs)의 광학적 특성을 포토루미네션스(photoluminescence, PL)와 시간분해 포토루미네션스(time-resolved PL, TRPL) 측정을 이용하여 분석하였다. In_(0.4)Al_(0.6)As 버퍼층은 기판의 온도를 320℃에서 580℃ 까지 다양하게 변화시키며 1 μm 성장하였으며, 그 위에 In_(0.5)Al_(0.5)As 층을 480℃에서 1 μm 성장한 후 InGaAs/InAlAs MQWs을 성장하였다. MQWs는 6-nm, 4-nm, 그리고 2.5-nm 두께의 In0.5Ga0.5As 양자우물과 10-nm 두께의 In_(0.5)Al_(0.5)As 장벽으로 이루어졌다. 4-nm QW과 6-nm QW로부터 PL 피크가 나타났으나, In0.4Al0.6As 성장온도 변화가 가장 큰(320℃에서 580℃까지 변화) 시료는 6-nm QW에서의 PL 피크만 나타났다. 낮은 온도(320℃에서 480℃까지 변화)에서 성장한 In_(0.4)Al_(0.6)As 버퍼층 위에 성장한 MQWs의 PL 특성이 우수하게 나타났다. 발광파장에 따른 TRPL 결과로 4-nm QW과 6-nm QW에서의 캐리어 소멸시간을 얻었다.

영어초록

The luminescence properties of In0.5Ga0.5As/In0.5Al0.5As multiple quantum wells (MQWs) grown on In_(0.4)Al_(0.6)As buffer layer have been investigated by using photoluminescence (PL) and time-resolved PL measurements. A 1-μm-thick In_(0.4)Al_(0.6)As buffer layers were deposited at various temperatures from 320℃ to 580℃ on a 500-nm-thick GaAs layer, and then 1-μm-thick In_(0.5)Al_(0.5)As layers were deposited at 480℃, followed by the deposition of the InGaAs/InAlAs MQWs. In order to study the effects of In_(0.4)Al_(0.6)As layer on the optical properties of the MQWs, four different temperature sequences are used for the growth of In_(0.4)Al_(0.6)As buffer layer. The MQWs consist of three In_(0.5)Al_(0.5)As wells with different well thicknesses (2.5-nm, 4.0-nm, and 6.0-nm-thick) and 10-nm-thick In_(0.5)Al_(0.5)As barriers. The PL peaks from 4-nm QW and 6-nm QW were observed. However, for the MQWs on the In_(0.4)Al_(0.6)As layer grown by using the largest growth temperature variation (320-580℃), the PL spectrum only showed a PL peak from 6-nm QW. The carrier decay times in the 4-nm QW and 6-nm QW were measured from the emission wavelength dependence of PL decay. These results indicated that the growth temperatures of In_(0.4)Al_(0.6)As layer affect the optical properties of the MQWs.

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