Band anti-crossing modelling and characterization of multi quantum well gainnas for photovoltaic application

• Main Author: Abd Samad, Muhammad Izzuddin
• Format: Thesis
• Language: English; English; English
• Published: 2021
• Subjects: TA1501-1820 Applied optics. Photonics
• Online Access: http://eprints.uthm.edu.my/1021/1/24p%20MUHAMMAD%20IZZUDDIN%20BIN%20ABD%20SAMAD.pdf; http://eprints.uthm.edu.my/1021/2/MUHAMMAD%20IZZUDDIN%20BIN%20ABD%20SAMAD%20COPYRIGHT%20DECLARATION.pdf; http://eprints.uthm.edu.my/1021/3/MUHAMMAD%20IZZUDDIN%20BIN%20ABD%20SAMAD%20WATERMARK.pdf; http://eprints.uthm.edu.my/1021/

A recent study of Ga0.952In0.048N0.016As0.984 /GaAs multi-quantum-well (MQW) p-i-n diode has reported that it is able to operate in near-infrared applications (800-1100nm). Nevertheless, there is no elucidations on the effect of indium (In) and nitrogen (N) fractions on electronic band transition, the localisation defect, and the impact of mesa active area on the electrical and photo-electrical properties of a diode. Hence, our motivations are simulating the GaInNAs electronic band transition, analyse the localisation defect and investigate an impact of mesa active area on the diode properties. The band anti crossing (BAC) modelling has been used to illustrate the GaInNAs electronic band transition with a bowing mechanism and resulted the relationship of redshift GaInNAs versus temperature. At the same time, temperature dependence photoluminescence (PL) measurement was used to validate the BAC modelling result and identify localisation defect at low temperature. Then, the connectivity between BAC and PL results was determined through Varshni analysis. The Varshni results were found synergies each other by close values of the temperature coefficient and GaInNAs energy bandgap at 0 K. On the other hand, an anomalies PL peaks energy at low temperature has been identified and indicated presence localisation defect. Next, the localisation energy parameter had been quantified via localisation energy analysis. The localisation energy parameters are resulted with maximum localisation energy = 9.44 eV at maximum localisation temperature = 40 K and delocalisation temperature =100 K. Furthermore, an investigation on the effect of the mesa active area on diodes were conducted using current-voltage measurements under dark and illumination. An increasing mesa active area was found increment in the dark current and ideality factor, while the value of short-circuit current density and efficiency parameters (photovoltaic) were decreased likewise. However, the value of turn on voltage, barrier height, open-circuit voltage and fill factor have constantly recorded and unaffected by increment of mesa active area.