Open AccessInfluence of V-Pits on the Turn-On Voltage of GaN-Based High Periodicity Multiple Quantum Well Solar Cells
Author(s) -
Marco Nicoletto,
Alessandro Caria,
Fabiana Rampazzo,
Carlo De Santi,
Matteo Buffolo,
Giovanna Mura,
Francesca Rossi,
Xuanqui Huang,
Houqiang Fu,
Hong Chen,
Yuji Zhao,
Gaudenzio Meneghesso,
Enrico Zai,
Matteo Meneghini
Publication year - 2023
Publication title -
ieee journal of photovoltaics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.023
H-Index - 72
eISSN - 2156-3403
pISSN - 2156-3381
DOI - 10.1109/jphotov.2023.3311891
Subject(s) - photonics and electrooptics
Based on combined electrical analysis, microscopy investigation, and two-dimensional simulations we investigate the influence of V-pits on the turn- on voltage and current-voltage characteristics of high periodicity InGaN-GaN multiple quantum wells solar cells. Experimental measurements indicate that the sample with the thinnest p-GaN layer presents an early turn- on , which is not present for thicker p-GaN layers. Through technology computer aided design (TCAD) simulations, we show that the early turn- on is due to the insufficient V-pit planarization, as demonstrated by scanning electron microscopy and transmission electron microscopy analysis. V-pits penetrate the junctions, and locally put the quantum well region in closer connection with the p-side contact. The results provide insight on the role of V-pits on the electrical performance of high-periodicity quantum well devices, and demonstrate the existence of a trade- off between the need of a thin p-GaN (to limit short-wavelength absorption) and a thicker p-GaN, to favor V-pit planarization.