Abstract
Optical properties of wurtzite AlGaN/GaN quantum well (QW) structures grown bymolecular-beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) onc-plane sapphire substrates have been investigated by means of photoluminescence(PL) and time-resolved photoluminescence (TRPL) at low temperature. ThePL spectra exhibit a blue-shifted emission of GaN/AlGaN QW nanostructuresby decreasing the barrier width, in contrast to the arsenide system (Pabla A Set al 1993 Appl. Phys. Lett. 63 752). This behavior is attributed to a redistributionacross the samples of the huge built-in electric field (several hundreds ofkV cm−1) induced by the polarization difference between wells and barriers. The trend of the barrierwidth dependence of the internal polarization field is reproduced by using simpleelectrostatic arguments. In addition, the effect of well width variation on the opticaltransition and decay time of GaN multiple quantum wells (MQWs) have been investigated,and it has been shown that the screening of the piezoelectric field and the electron–holeseparation are strongly dependent on the well thickness and have a profound effect onthe optical properties of the GaN/AlGaN MQWs. The time-resolved PL spectraof 3 nm well MQWs reveal that the spectral peak position shifts toward lowerenergies as the decay time increases and becomes red-shifted at longer decay times.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
