High Reflectivity p-Type Doped Distributed Bragg Reflectors Using ZnSe/MgS Superlattices

Abstract

Undoped and p-type doped distributed Bragg reflectors (DBRs) have been grown by molecular beam epitaxy using ZnSe layers for the high refractive index material and ZnSe/MgS superlattices (SLs) for the low index material. The ZnSe/MgS SLs consist of 22.5 periods with a period length of 2.5 nm as confirmed by high-resolution X-ray diffraction measurements. A reflectivity of the p-type doped DBR higher than 99% at 522 nm has been achieved. The low temperature photoluminescence spectrum of the p-type doped DBR shows a strong donor-acceptor pair recombination peak at 2.686 eV.

An Investigation on Structural and Optical Properties of Zn1−xMgxS Thin Films Deposited by RF Magnetron Co-Sputtering Technique

“…Two electronic transition bands have been observed, one at 450 nm for all the samples and the other at around 375 nm, that increase alongside the Mg concentration. According to O′Neil et al [42] and Spanhel et al [43], the excitonic emission is located near the absorption edge of the particles. From Figure 7, the absorption edges of the films were in between 300 to 380 nm, which comply with PL data in Figure 9.…”

Combined (ZnSe/MgS)/ZnCdSe Bragg Reflectors Grown Using ZnS as a Sulphur Source

“…For example, Suemune et al have grown a 5-period ZnSe/(ZnSe/MgS) distributed Bragg reflector (DBR) with a 92% reflectivity by metal-organic vapor phase epitaxy [4]. Kruse et al have demonstrated 17-period DBR of the same type with 99% reflectivity, grown by molecular beam epitaxy (MBE) using a valved cracker cell as a sulphur source [5].Earlier Bradford et al have suggested to employ ZnS as a sulphur source to grow MgS/ZnSe quantum wells (QWs), using the efficient Mg-Zn exchange interaction which is due to the much stronger Mg-S binding energy as compared to the Zn-S one, although they have not applied this technique to DBRs [6]. This paper reports on the studies of novel design (ZnSe/MgS)/ZnCdSe DBRs grown by MBE using ZnS as a sulphur source.…”

High-reflectivity broadband distributed Bragg reflector lattice matched to ZnTe

“…Our DBR structure was grown using molecular beam epitaxy (MBE). We controlled layer thickness by insitu reflectivity, 18 which allowed us to grow quarter-wave thick layer with precision of 1 nm. In this work we used a GaAs substrate covered by a thin ZnSe layer, followed by a thick ZnTe buffer.…”