TY - JOUR
T1 - Precise determination of polarization fields in c-plane GaN/Al x Ga1-x N/GaN heterostructures with capacitance–voltage-measurements
AU - Susilo, Norman
AU - Schilling, Marcel
AU - Narodovitch, Michael
AU - Yao, Hsin-Hung
AU - Li, Xiaohang
AU - Witzigmann, Bernd
AU - Enslin, Johannes
AU - Guttmann, Martin
AU - Roumeliotis, Georgios G.
AU - Rychetsky, Monir
AU - Koslow, Ingrid
AU - Wernicke, Tim
AU - Niermann, Tore
AU - Lehmann, Michael
AU - Kneissl, Michael
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): BAS/1/1664-01-01, URF/1/3437-01-01, REP/1/3189-01-01
Acknowledgements: This work was supported by the German Federal Ministry of Education and Research (BMBF) within the Advanced UV for Life project and by the Deutsche Forschungsgemeinschaft (DFG) within the Collaborative Research Centre Semiconductor Nanophotonics (SFB 787). Part of this work was also co-funded by the Erasmus+ programme of the European Union. The KAUST authors acknowledge the support of KAUST Baseline BAS/1/1664-01-01, KAUST CRG URF/1/3437-01-01, and GCC REP/1/3189-01-01.
PY - 2019/4/23
Y1 - 2019/4/23
N2 - Due to changes in the spontaneous and piezoelectric polarization, AlGaN/GaN heterostructures exhibit strong polarization fields at heterointerfaces. For quantum wells, the polarization fields lead to a strong band bending and a redshift of the emission wavelength, known as quantum-confined Stark effect. In this paper the polarization fields of thin AlGaN layers in a GaN matrix were determined by evaluating the changes in the depletion region width in comparison to a reference sample without heterostructure using capacitance–voltage-measurements. The polarization fields for Al0.09Ga0.91N (0.6 ± 0.7 MV cm−1), Al0.26Ga0.74N (2.3 ± 0.6 MV cm−1), Al0.34Ga0.66N (3.1 ± 0.6 MV cm−1), Al0.41Ga0.59N (4.0 ± 0.7 MV cm−1) and Al0.47Ga0.53N (5.0 ± 0.8 MV cm−1) heterostructures were determined. The results of the field strength and field direction of all samples are in excellent agreement with values predicted by theory and a capacitance–voltage based Poisson-carrier transport simulation approach giving experimental evidence for a nonlinear increasing polarization field with Al-concentration.
AB - Due to changes in the spontaneous and piezoelectric polarization, AlGaN/GaN heterostructures exhibit strong polarization fields at heterointerfaces. For quantum wells, the polarization fields lead to a strong band bending and a redshift of the emission wavelength, known as quantum-confined Stark effect. In this paper the polarization fields of thin AlGaN layers in a GaN matrix were determined by evaluating the changes in the depletion region width in comparison to a reference sample without heterostructure using capacitance–voltage-measurements. The polarization fields for Al0.09Ga0.91N (0.6 ± 0.7 MV cm−1), Al0.26Ga0.74N (2.3 ± 0.6 MV cm−1), Al0.34Ga0.66N (3.1 ± 0.6 MV cm−1), Al0.41Ga0.59N (4.0 ± 0.7 MV cm−1) and Al0.47Ga0.53N (5.0 ± 0.8 MV cm−1) heterostructures were determined. The results of the field strength and field direction of all samples are in excellent agreement with values predicted by theory and a capacitance–voltage based Poisson-carrier transport simulation approach giving experimental evidence for a nonlinear increasing polarization field with Al-concentration.
UR - http://hdl.handle.net/10754/632546
UR - https://iopscience.iop.org/article/10.7567/1347-4065/ab09dd/meta
UR - http://www.scopus.com/inward/record.url?scp=85070746856&partnerID=8YFLogxK
U2 - 10.7567/1347-4065/ab09dd
DO - 10.7567/1347-4065/ab09dd
M3 - Article
SN - 0021-4922
VL - 58
SP - SCCB08
JO - Japanese Journal of Applied Physics
JF - Japanese Journal of Applied Physics
IS - SC
ER -