Gas source MBE growth of GaN rich side of GaN1 − P using ion-removed ECR radical cell

Abstract

Abstract GaN-rich side of GaN 1 − x P x alloy are grown on (0 0 0 1) sapphire substrates by electron cyclotron resonance molecular beam epitaxy (ECR-MBE) using an ion removed ECR radical cell after the growth of high-quality GaN layers. GaN 1 − x P x exhibits potentially large variation of band-gap energy with P composition due to its large bowing. Maximum P composition of x = 0.015 is obtained. However, at the growth condition of high PH 3 flow rate, phase separation into GaN-rich GaN 1 − x P x and GaP-rich GaP 1 − y N y is observed. Near band edge excitonic photoluminescence (PL) peak from GaN-rich side of GaN 1 − x P x layers shows large red shift with P composition. It suggests that the direct band edge of GaNP alloy shows large bowing.