Anomalous Temperature Dependence of Photoluminescence Caused by Non-Equilibrium Distributed Carriers in InGaN/(In)GaN Multiple Quantum Wells

Abstract

An increase of integrated photoluminescence (PL) intensity has been observed in a GaN-based multiple quantum wells (MQWs) sample. The integrated intensity of TDPL spectra forms an anomalous variation: it decreases from 30 to 100 K, then increases abnormally from 100 to 140 K and decreases again when temperature is beyond 140 K. The increased intensity is attributed to the electrons and holes whose distribution are spatial non-equilibrium distributed participated in the radiative recombination process and the quantum barrier layers are demonstrated to be the source of non-equilibrium distributed carriers. The temperature dependence of this kind of spatial non-equilibrium carriers’ dynamics is very different from that of equilibrium carriers, resulting in the increased emission efficiency which only occurs from 100 to 140 K. Moreover, the luminescence efficiency of MQWs with non-equilibrium carriers is much higher than that without non-equilibrium carriers, indicating the high luminescence efficiency of GaN-based LEDs may be caused by the non-equilibrium distributed carriers. Furthermore, a comparison analysis of MQWs sample with and without hydrogen treatment further demonstrates that the better quantum well is one of the key factors of this anomalous phenomenon.

The Investigation of Carrier Leakage Mechanism Based on ABC-Models in InGaN/GaN MQW and Its Effect on Internal Quantum Efficiency under Optical Excitation

“…As a result, the IQE when using 325 nm laser source is higher than that with 405 nm laser. The physical mechanism has been discussed in detail in our previous work [26]. Here, the injected carrier can also significantly enhance the IQE, which provide evidence to the huge effect of carrier leakage on the IQE from an opposite direction.…”

Zero-Thermal-Quenching Layered Metal Halide Perovskite

“…Similarly, as shown in Figure a, the PL intensity of Rb 3 (Cd 0.80 Mn 0.20 ) 2 Cl 7 SCs monotonically decreased as a function of temperature. , Temperature dependence of luminescence can be described by the Arrhenius equation where I 0 is the PL intensity at 0 K, I Mn 2+ ( T ) is the intensity at different temperatures, E b is the exciton binding energy, A is a constant related to nonradiative to radiative rate, and K B is the Boltzmann constant. The exciton binding energy of Rb 3 (Cd 0.80 Mn 0.20 ) 2 Cl 7 SCs is approximately 182 meV, which is higher than that of previously reported LMHP materials − (Figure b).…”

“…29−31 Similarly, as shown in Figure 4a, the PL intensity of Rb 3 (Cd 0.80 Mn 0.20 ) 2 Cl 7 SCs monotonically decreased as a function of temperature. 32,33 Temperature dependence of luminescence can be described by the Arrhenius equation ( )…”