Temperature Dependence of Carrier Coupling in an Asymmetric Double-Quantum-Well

The understanding of the temperature dependence of carrier dynamics in an asymmetric double-quantum-well is essentially important for the realization of room temperature efficient photonic devices.As the temperature increases,the carriers will be thermally evaporated into the barrier layer from quantum wells and then some of them will be recaptured by the quantum wells,i.e.carrier coupling takes place between the different quantum wells when the temperature increases.The ratio of photoluminescence intensity of different quantum wells can reflect the distribution of carriers in each well.The temperature dependence of the ratio of photoluminescence intensity in an asymmetric double-quantum-well has not been reported until now.The temperature dependence of the carrier coupling in an asymmetric double-quantum-well was simulated by using the coupling multiple-quantum-well model of carrier dynamics.It is shown that the ratio of photoluminescence intensity of each well strongly depends on the dif-(ference) of thermal activation energies.The maximum of the ratio of photoluminescence intensity depends exponentially on the difference of thermal activation energy,while the temperature corresponding to the maximum depends linearly on the difference of thermal activation energies.This simulation method can be used to study carrier thermal escape and re-trapping in quantum-dot-quantum-well heterostructures formed by sub-monolayer deposition,which will be published in the near future.