High reflectivity symmetrically strained $ZnxCdyMg1−x−ySe$-based distributed Bragg reflectors for current injection devices

Distributed Bragg reflectors (DBRs) with different numbers of periods were grown by molecular beam epitaxy from $ZnxCdyMg1−x−ySe$-based materials on InP substrates. The alternating ZnCdSe/ZnCdMgSe layers were symmetrically strained to the InP substrate greatly simplifying the growth process and increasing the uniformity. High crystalline quality was also achieved in these structures. A maximum reflectivity of 99% was obtained for a DBR with 24 periods. Chlorine doped (n-type) DBRs were grown and their electrical and optical properties were investigated. Electrochemical capacitance–voltage profiling indicated that the doping concentrations of the ZnCdSe and ZnCdMgSe layers were $4×1018$ and $2×1018 cm−3,$ respectively. The reflectivity of the doped DBR structures was comparable to that of the undoped ones.