Quantitative study on the mechanisms underlying the phonon bottleneck effect in InN/InGaN multiple quantum wells

Herein, we quantitatively investigated the mechanisms of interfacial phonon mismatch and quantum confinement underlying the phonon bottleneck effect in InN/InxGa(1−x)N multiple quantum wells. Obvious extension of carrier thermalization with the longest relaxation time of 4.75 ns due to an enhanced phonon bottleneck effect was observed. It was found that a stronger quantum confinement could effectively reduce carrier relaxation rate via improving the elastic carrier–carrier scattering, while a larger phonon mismatch may give a higher initial carrier temperature due to the reflection of optical phonons and probably confinement of quasi-optical phonons. This study provides an essential theoretical insight into photovoltaic and other optoelectronic devices aiming to reduce the carrier relaxation rate via the phonon bottleneck effect.Herein, we quantitatively investigated the mechanisms of interfacial phonon mismatch and quantum confinement underlying the phonon bottleneck effect in InN/InxGa(1−x)N multiple quantum wells. Obvious extension of carrier thermalization with the longest relaxation time of 4.75 ns due to an enhanced phonon bottleneck effect was observed. It was found that a stronger quantum confinement could effectively reduce carrier relaxation rate via improving the elastic carrier–carrier scattering, while a larger phonon mismatch may give a higher initial carrier temperature due to the reflection of optical phonons and probably confinement of quasi-optical phonons. This study provides an essential theoretical insight into photovoltaic and other optoelectronic devices aiming to reduce the carrier relaxation rate via the phonon bottleneck effect.