Polaron effects on the linear and nonlinear intersubband optical absorption coefficients in quantum wells with asymmetrical semi-exponential potential

• Asymmetrical semi-exponential quantum wells have been proposed.
• The unperturbed eigenfunctions and energy eigenvalues are obtained by solving Schrödinger equation. And the wave function and energy of the system are acquired through perturbation method.
• Absorption coefficients are strongly affected by parameters of confinement potential.
• Absorption coefficients are highly enhanced when polaron effects are considered.

Linear and nonlinear intersubband optical absorption coefficients in quantum wells with asymmetrical semi-exponential potential are studied theoretically. We obtain unperturbed eigenfunctions and the energy eigenvalues by means of solving Schrödinger equation within the framework of effective mass approximation. The wave functions and energies with consideration of polaron are acquired through perturbation method. Besides, the analytic expressions of optical absorption coefficients are obtained using compact-density-matrix approach and iterative method. The results of calculation show that optical absorption is enhanced when effects of polaron are considered. Additionally, the parameters of confinement potential have great influences on optical absorption.