Proceedings of the European Summer School of Photovoltaics 4 – 7 ...

Fig. 2. The symmetric (004) HRXRD scans for the MQW structures
Tabl. 1. Parameters of investigated MQW structures grown on n-type doped
substrates determined from HRXRD measurements
Sample
Thickness [nm] QW composition [%]
Quantum
well
Barrier Indium Nitrogen
NI 43n 14.5 29 14.5 0.38
NI 45n 14.7 31 16.6 0.5
NI 46n 14.8 30.2 17 0.55
NI 58n 6 29.5 12.1 0.41
Fig. 3. The nitrogen content in In y
Ga 1-y
As 1-x
N x
quantum wells grown on
SI GaAs substrate as a function of the growth temperature T g
--+++
Tabl. 2. The ground state energy values of MQW structures determined from
PL and CER spectra
Sample
PL
E GS
[eV]
CER
NI 43n 14.5 1.201
NI 45n 1.183 1.184
NI 46n 1.177 1.176
NI 58n 1.218 1.212
Fig. 5. PL spectra of InGaAsN/GaAs MQW structures grown at different
temperatures
Fig. 4. CER spectra of InGaAsN/GaAs MQW structures grown at different
temperatures
112
Measured CER and PL spectra of the MQW structures grown
at different temperatures are shown in Fig. 4 and 5, respectively.
Optical transitions marked in Fig. 4, testify a good optical quality
of the MQW region.
The maximum intensity of the photoluminescence is observed
for NI 46 structure, which was grown in highest temperature of
585°C. Good material quality of this structure was also confirmed
by HRXRD measurements.
Conclusions
This paper presents the influence of the AP-MOVPE epitaxial process
growth temperature on the optical and structural properties
of heterostructures containing InGaAsN quantum wells. The best
Elektronika 6/2012