Electron transport in unipolar InGaN/GaN multiple quantum well structures grown by NH{sub 3} molecular beam epitaxy

Journal Article · Thu May 14 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4919750· OSTI ID:22410196

Browne, David A.; Speck, James S. ^[1]; Mazumder, Baishakhi ^[1]; Wu, Yuh-Renn ^[2]

---

1. Materials Department, University of California, Santa Barbara, California 93106 (United States)
2. Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China)

Unipolar-light emitting diode like structures were grown by NH{sub 3} molecular beam epitaxy on c plane (0001) GaN on sapphire templates. Studies were performed to experimentally examine the effect of random alloy fluctuations on electron transport through quantum well active regions. These unipolar structures served as a test vehicle to test our 2D model of the effect of compositional fluctuations on polarization-induced barriers. Variables that were systematically studied included varying quantum well number from 0 to 5, well thickness of 1.5 nm, 3 nm, and 4.5 nm, and well compositions of In{sub 0.14}Ga{sub 0.86}N and In{sub 0.19}Ga{sub 0.81}N. Diode-like current voltage behavior was clearly observed due to the polarization-induced conduction band barrier in the quantum well region. Increasing quantum well width and number were shown to have a significant impact on increasing the turn-on voltage of each device. Temperature dependent IV measurements clearly revealed the dominant effect of thermionic behavior for temperatures from room temperature and above. Atom probe tomography was used to directly analyze parameters of the alloy fluctuations in the quantum wells including amplitude and length scale of compositional variation. A drift diffusion Schrödinger Poisson method accounting for two dimensional indium fluctuations (both in the growth direction and within the wells) was used to correctly model the turn-on voltages of the devices as compared to traditional 1D simulation models.

• OSTI ID: 22410196
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 18; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
AMMONIA
COMPARATIVE EVALUATIONS
ELECTRIC POTENTIAL
ELECTRONS
FLUCTUATIONS
GALLIUM NITRIDES
INDIUM COMPOUNDS
LIGHT EMITTING DIODES
MOLECULAR BEAM EPITAXY
POISSON EQUATION
POLARIZATION
QUANTUM WELLS
SAPPHIRE
SCHROEDINGER EQUATION
TEMPERATURE DEPENDENCE
TWO-DIMENSIONAL SYSTEMS