The investigation of photoluminescence properties in InxGa1-xN/GaN multiple quantum wells structures with varying well number

The photoluminescence (PL) properties of InGaN/GaN multiple quantum wells (MQWs) samples with a different quantum well number (two, three, and four) grown by molecular beam epitaxy have been studied in the temperature range between 3 and 300 K. The redshift-blueshift-redshift in the PL peak energy of InGaN well, which is known that as S-shaped behavior, is observed with increasing temperature in the investigated samples. S-shaped behavior is associated with carrier localization states and inhomogeneity in InGaN/GaN MQWs samples. This behavior is explained with the theoretical band tail model. The parameters showing the effect of carrier localization degree are determined and discussed in detail. Furthermore, it is presented the activation energy of charge carriers by using InGaN related-normalized PL peak intensity as a function of the reverse of temperature and Arrhenius function for all samples. The highest PL intensity is obtained in sample B with 3-QWs. Determining carrier localization effect and activation energy plays a vital role in luminescence efficiency and quality of InGaN/GaN MQWs devices.

Automated summary

The photoluminescence properties of InGaN/GaN multiple quantum wells with different quantum well numbers were studied in this research. The observed shift in the peak energy of photoluminescence with increasing temperature is explained by the S-shaped behavior. The localization states of carriers and the inhomogeneity in the samples contribute to this behavior. The study also discusses the parameters that characterize the degree of carrier localization and the activation energy.