Gavalajyan Sargis P, Mantashian Grigor A, Kharatyan Gor Ts, Sarkisyan Hayk A, Mantashyan Paytsar A, Baskoutas Sotirios, Hayrapetyan David B
Department of General Physics and Quantum Nanostructures, Russian-Armenian University, 123 Hovsep Emin Str., Yerevan 0051, Armenia.
Institute of Chemical Physics after A.B. Nalbandyan of NAS RA, 5/2 Paruyr Sevak St., Yerevan 0014, Armenia.
Nanomaterials (Basel). 2023 Apr 18;13(8):1393. doi: 10.3390/nano13081393.
The current work used the effective mass approximation conjoined with the finite element method to study the exciton states in a conical GaAs quantum dot. In particular, the dependence of the exciton energy on the geometrical parameters of a conical quantum dot has been studied. Once the one-particle eigenvalue equations have been solved, both for electrons and holes, the available information on energies and wave functions is used as input to calculate exciton energy and the effective band gap of the system. The lifetime of an exciton in a conical quantum dot has been estimated and shown to be in the range of nanoseconds. In addition, exciton-related Raman scattering, interband light absorption and photoluminescence in conical GaAs quantum dots have been calculated. It has been shown that with a decrease in the size of the quantum dot, the absorption peak has a blue shift, which is more pronounced for quantum dots of smaller sizes. Furthermore, the interband optical absorption and photoluminescence spectra have been revealed for different sizes of GaAs quantum dot.
当前的工作采用有效质量近似结合有限元方法来研究锥形 GaAs 量子点中的激子态。特别地，研究了激子能量对锥形量子点几何参数的依赖性。一旦求解了电子和空穴的单粒子本征值方程，关于能量和波函数的可用信息就被用作输入来计算激子能量和系统的有效带隙。已估计出锥形量子点中激子的寿命，并表明其在纳秒范围内。此外，还计算了锥形 GaAs 量子点中与激子相关的拉曼散射、带间光吸收和光致发光。结果表明，随着量子点尺寸的减小，吸收峰发生蓝移，对于较小尺寸的量子点，这种蓝移更为明显。此外，还揭示了不同尺寸 GaAs 量子点的带间光吸收和光致发光光谱。
