Energy difference between electron subbands in $AlInN∕GaInN$ quantum wells studied by contactless electroreflectance spectroscopy

Contactless electroreflectance (CER) spectroscopy has been applied to study the energy difference between electron subbands in $AlInN∕GaInN$ multiquantum wells (MQWs). Due to the strong built-in electric field, which is typical for III-nitrides, interband transitions between all QW subbands have been clearly observed. The energy difference between electron subbands has been found analyzing the interband transitions between the first hole subband and electron subbands. It has been shown that this difference is consistent with the results obtained by using photoinduced absorption of intersubband transitions. It shows that CER is an excellent method to study the energy difference between electron subbands in $Al(In)N∕Ga(In)N$ QWs.