Wavefunctions and optical gain in Al0.8Ga0.2As/GaAs0.8P0.2 type-I QW-heterostructure under external electric field

摘要

Optical transition strength are observed to be affected in Al0.8Ga0.2As/GaAs0.8P0.2 type-I QW-heterostructure under external electric field. This paper reports optical gain realized in Al0.8Ga0.2As/GaAs0.8P0.2 type-I QW-heterostructure (varying well width 6nm–22nm). Band alignment, wavefunctions and optical gain of the nano-scale heterostructure under electromagnetic field perturbation is reported. The 6×6 diagonalised k⃗. p⃗ Hamiltonian matrix is evaluated and Luttinger-Kohn model has been applied for the band structure calculations. Optical gain spectrum in the QW-heterostructure under external electric fields of (20, 40 and 60 kV/cm) is calculated. Optical gain (x and z polarizations) of the nano-scale heterostructure under well width and temperature variations is investigated. The optical gain spectrum of the heterostructure is seen to gradually rise with shrinking well width. Also the optical gain curve shows a decrease in gain with rising temperature levels. For a charge carrier injection of 4 × 10/cm the optical gain is ∼220 under input x polarization [100] and ∼625 under z polarization [001] at 300K. The heterostructure is seen to be operating in the energy range of 1.5 to 1.75 eV (708 to 826 nm). Thus, a wide range wavelength tuning is achievable.