Growth and Characterization of p-InGaN/i-InGaN/n-GaN Double-Heterojunction Solar Cells on Patterned Sapphire Substrates

Abstract

In this letter, InGaN-based solar cells with a p-InGaN/i-InGaN/n-GaN double-heterojunction structure were fabricated and characterized. Two kinds of sapphire substrates [i.e., a conventional sapphire substrate (CSS) and a patterned sapphire substrate (PSS)] were used for epitaxial growth. Both the solar cells grown on the CSS and the PSS demonstrated a high open-circuit voltage of 2.05 and 2.08 V, respectively. However, the short-circuit current of the solar cells grown on the PSS showed an improvement of 27.6% compared with that of the cells grown on the CSS. Such observation could be attributed to low edgedislocation density and the increase in the light-absorption path by the scattering of interface incident light between the substrate and the epitaxial layer for the solar cell grown on the PSS

High quality thick InGaN nanostructures grown by nanoselective area growth for new generation photovoltaic devices

“…However, thick InGaN nanostructures specifically designed as solar cells were seldom reported and their properties have not been well studied . Increase in conversion efficiency has been reported on the InGaN MQWs based solar cells conventionally grown on patterned sapphire substrates . This process reduces dislocation density in the buffer and thus increases the performance.…”

Conversion Efficiency Improvement of InGaN/GaN Multiple-Quantum-Well Solar Cells With <italic>Ex Situ</italic> AlN Nucleation Layer

“…The V OC of this paper is >2 V due to blue range absorption of the InGaN/GaN MQWs [23], [24]. Besides, the higher V OC of SC II should be attributed to the reduction of dislocation of GaN layer with ex situ AlN nucleation layer [25]. Fig.…”

Efficiency Improvement of Short-Period InGaN/GaN Multiple-Quantum Well Solar Cells With <formula formulatype="inline"><tex Notation="TeX">${\hbox{H}} _{2}$</tex></formula> in the GaN Cap Layer

“…The of SC III (2.34 V) exhibited a 3.5% increase compared with that of SC II (2.26 V). The dislocation density of the GaN layer was reduced using PSS [16]. The reduced dislocation density of the GaN layer suppressed the photogenerated carrier to recombine at the defect-related center (3.5%) of SC II.…”

“…and subsequently improved the and of SC III. Furthermore, light scattering on the GaN and PSS interface increased the light-travel path of the incident irradiance in SC III[17]. The increased light-travel path through the active region of the InGaN/GaN SPMQW enhanced light absorption and improved the and of SC III.…”