The authors propose and demonstrate the fabrication of InN∕GaN multiple quantum well (MQW) consisting of 1 ML and fractional monolayer InN well insertion in GaN matrix under In-polarity growth regime. Since the critical thickness of InN epitaxy on GaN is about 1 ML and the growth temperature for 1 ML InN insertion can be remarkably higher, the proposed MQW structure can avoid/reduce generation of misfit dislocation, resulting in higher quality MQW-structure nature in principle than former InN-based MQWs. The proposed InN∕GaN MQWs are potentially applicable to room temperature operating excitonic devices working in short-wavelength visible colors.

Structural and optical characterization of InGaN/GaN multiple quantum wells grown by molecular beam epitaxyThe authors propose and demonstrate fine structure novel InN/GaN multiple quantum wells ͑MQWs͒ consisting of ultimately thin InN wells around 1 ML inserted in a GaN matrix grown under In-polarity growth regime by molecular beam epitaxy. Since the critical thickness of InN epitaxy on the c-plane GaN is about 1 ML and also the growth temperature for 1 ML InN insertion can be remarkably higher than conventional one, the proposed MQW structure can avoid new generation of misfit dislocation at the heterointerface, in principle, and results in high quality MQW structure due to the effects of enhanced surface migration at higher temperatures. It is shown that demonstrated 1 ML InN/GaN MQW structures indicate surprisingly higher structural quality/ properties than those former-reported InN-based heterostructures. Self-ordering mechanism arising from immiscibility nature in between InN and GaN will also contribute for depositing sharp and atomically flat InN well. The proposed MQW structure has physically and practically important meanings leading to room temperature operating GaN-based excitonic devices and also efficient photonic devices working in short wavelength visible colors.