Molecular Beam Epitaxy

13III‐Nitride Quantum Dots for Optoelectronic Devices

Pallab Bhattacharya Thomas Frost Shafat Jahangir Saniya Deshpande and Arnab Hazari

Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA

13.1 Introduction

Recent demand for visible and ultra‐violet light‐emitting diodes (LEDs) and lasers is immense, due to their numerous applications in the fields of solid‐state lighting, optical data storage, plastic fiber communication, full‐color mobile projectors, heads‐up displays, and in quantum cryptography and computing [1,2]. Most research and development into these light sources is being done using nitride‐based materials, where the emission can be tuned from deep ultra‐violet in AlN (∼6 eV) to the near infrared by using InN (∼0.7 eV). Since the first report of a blue‐emitting InGaN/GaN quantum well (QW) LED in 1995 [3], much progress has been made in extending the emission to longer wavelengths through the incorporation of more indium in the InGaN QWs [4–11]. While the first blue‐emitting laser was demonstrated by Nakamura in 1996 [12], it has since become increasingly difficult to grow and fabricate lasers at longer wavelengths. It was only as recently as 2009 that the first green‐emitting laser was demonstrated using InGaN/GaN QWs [13], and red emission has yet to be achieved with QWs. To fully realize the potential of these nitride‐based LEDs and lasers, it is necessary to further extend the emission wavelength of these devices ...