Influence of Width of Left Well on Intersubband Transitions in Al_xGa_1-x N/GaN Double Quantum Wells

Influence of width of left well in Al_xGa_1-xN/GaN double quantum wells (DQWs) on absorption coefficients and wavelengths of the intersubband transitions (ISBTs) is investigated by solving the Schrödinger and Poisson equations self-consistently. When the width of left well is 1.79nm, three-energy-level DQWs are realized. The ISBT between the first odd and second odd order subbands (the 1_odd-2_odd ISBT) has a comparable absorption coefficient with the 1 _odd-2_even ISBT. Their wavelengths are located at 1.3 and 1.55μm, respectively. When the width of left well is 1.48nm, a four-energy-level DQWs is realized. The calculated results have a possible application to ultrafast two-colour optoelectronic devices operating within the optical communication wavelength range