Lattice-matched III-nitride structures comprising BAlN, BGaN, and AlGaN for ultraviolet applications

Feras Alqatari,Xiaohang Li,Kuang-Hui Li,Muhammad Sajjad,Udo Schwingenschlögl,Ronghui Lin

doi:10.1088/2053-1591/ac1caa

Feras Alqatari, Xiaohang Li + Show 4 more

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https://doi.org/10.1088/2053-1591/ac1caa

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Abstract

The optical properties of BAlN, BGaN and AlGaN ternary alloys are investigated using hybrid density functional for the design of lattice-matched optical structures in the ultraviolet spectrum. The calculated AlGaN properties agree well with previous reports, validating the model. A peculiar non-monotonic behavior of the refractive index as a function of the boron composition is found. The results of this calculation are interpolated to generate a three-dimensional dataset, which can be employed for designing a countless number of lattice-matched and –mismatched heterostructures. These heterostructures could span a range of operating wavelengths well into the deep ultraviolet with refractive indices ranging from 1.98 to 2.41 for AlN at 0 eV and GaN near the GaN bandgap, respectively. An example is shown where a lattice-matched heterostructure, AlN/B0.108Ga0.892N, is applied for DBR applications with a large index difference. A DBR comprising the AlN/B0.108Ga0.892N heterostructure at the UV wavelength of 375 nm is found to exceed 93% peak reflectivity with only 10 pairs and reaches 100% reflectivity with 35 pairs. For a chosen design with 25 pairs, the DBR has a peak reflectivity of 99.8% and a bandwidth of 26 nm fulfilling the requirements of most devices especially ultraviolet vertical-cavity surface emitting lasers.

Highlights

The refractive indices of the three known that such local functionals could ternary alloys and the lattice constants were severely underestimate the bandgaps, redshift employed to identify lattice-matched material absorption spectra, miss excitonic features in pairs with a large index difference for distributed Bragg reflectors (DBRs)
This lasers are rapidly rising for vital applications leads to relatively complex growth methods for such as sterilization, data storage, biochemical the realization of near lattice-matched sensing, atomic clocks, and communication[4
14 lattice-matched material pairs with various pairs can be utilized to compute the theoretical refractive index differences important for bandwidth Δλ of the material pair at various minimized structural thickness and strain wavelengths for the distributed Bragg reflectors (DBRs) according to Equation management

Summary

Introduction

The refractive indices of the three known that such local functionals could ternary alloys and the lattice constants were severely underestimate the bandgaps, redshift employed to identify lattice-matched material absorption spectra, miss excitonic features in pairs with a large index difference for DBR To design III-nitride optical structures (c) show the comparison between Segura’s and including DBRs for UV applications, it is our index values.

Results

Conclusion