Photoluminescence study of non-polar m-plane InGaN and nearly strain-balanced InGaN/AlGaN superlattices

Abstract

Photoluminescence (PL) spectroscopy of nonpolar m-plane InGaN thin films with indium composition up to 21% and nearly strain-balanced In0.09Ga0.91N/Al0.19Ga0.81N superlattices grown by plasma-assisted molecular beam epitaxy was performed as a function of temperature. The experimental transition energies are consistently lower than the calculation based on structural parameters extracted from x-ray diffraction measurements. This indicates the presence of indium composition fluctuations in InGaN and hence local bandgap reduction that produces charge localization centers. The spectral width of the low-temperature PL of our m-plane InGaN/AlGaN superlattices is narrower than previously reported for m-plane InGaN/GaN quantum wells grown by MOCVD. The PL integrated intensity drops rapidly, though, as the temperature is increased to 300 K, indicating strong non-radiative recombination at room temperature. Time-resolved PL at low temperatures was performed to characterize the relaxation time scales in an undoped and a doped superlattice.

Photoluminescence Study of Carrier Localization and Recombination in Nearly Strain‐Balanced Nonpolar InGaN/AlGaN Quantum Wells

“…The agreement between the measured PL energies of the two samples confirms that they have the intended identical layer structures. Moreover, the decay times, τ 1 and τ , of localization centers, A and C are quantitatively similar, and have analogous temperature [ 19 ] and magnetic field dependence curves (see the following discussion). In contrast, the decay time τ 2 of localization center B is much longer.…”

“…We previously found that the experimental PL energies of m‐plane InGaN/AlGaN superlattices are systematically lower than the calculations made using generally accepted material parameters. [ 19 ] At 8 K, the experimental PL peaks are 3.095 eV (sample G) and 3.079 eV (sample H), while the calculated PL energies are 3.299 eV (sample G) and 3.302 eV (sample H). The discrepancy was attributed to the inhomogeneous distribution of In composition, [ 19 ] but may also be due to other excitonic effects that were not included in the calculation.…”

“…Figure1. Temperature dependence of PL FWHM for: a) undoped sample G,[19] and b) doped sample H. The data in panel (a) was reproduced from Ref [19]. with permission of AIP Publishing.…”

Exception of terahertz quantum cascade laser based on new material systems

“…Saha等人 [54] 于 2017年对非极性GaN材料的量子阱在不同的温度下量 子级联结构的吸收系数进行了计算. 2019年, Cao等 人 [55] 设计了基于m平面非极性GaN材料系统的薄膜. [38] .…”

Numerical Investigation into Optoelectronic Performance of InGaN Blue Laser in Polar, Non-Polar and Semipolar Crystal Orientation

“…Semipolar (112 ̅ 2) and (2021 ̅̅̅ )-oriented blue laser diodes grown on sapphire substrate and lasing at peak wavelength of 439 and 456 nm were reported for the first time [10,11]. The optical properties of non-polar m-plane InxGa1-xN (x ≤ 0.21) thin films have been characterized by Cao et al via photoluminescence spectroscopy [12]. A work by Xing et al demonstrated semipolar (112 ̅ 2)-oriented GaN epitaxial film growth on m-plane sapphire substrate with significantly reduced defect densities [13].…”