Temperature dependent diode and photovoltaic characteristics of graphene-GaN heterojunction

Abstract

Understanding the charge carrier transport characteristics at the graphene-GaN interface is of significant importance for the fabrication of efficient photoresponsive devices. Here, we report on the temperature dependent diode and photovoltaic characteristics of a graphene/n-GaN heterostructure based Schottky junction. The graphene/n-GaN heterojunction showed rectifying diode characteristics and photovoltaic action with photoresponsivity in the ultra-violet wavelength. The current-voltage characteristics of the graphene/n-GaN heterojunction device were investigated under dark and light illumination with changes in temperature. Under dark conditions, an increase in the forward bias current as well as saturation current was observed, and a decrease in the device ideality factor was obtained with an increase in temperature. Under illumination of light, a decrease in the open circuit voltage (Voc) and an increase in the short circuit current density (Jsc) was obtained with an increase in temperature. The increase in saturation current and carrier recombination with the increase in temperature leads to a reduction in Voc, while the photo-generated carrier increases in the heterojunction interface at higher temperatures contributing to the increase in Jsc. The observed temperature dependent device characteristics of the graphene/n-GaN heterojunction can be significant to understand the junction behavior and photovoltaic action.

Schottky Barrier Diode Characteristics of Graphene-GaN Heterojunction with Hexagonal Boron Nitride Interfacial Layer

“…The peak positions for G and 2D peaks are in the range of 1592–1598 cm −1 and 2682–2686 cm −1 , respectively. Previously, we have reported that the variation of G (≈1590 cm −1 ) and 2D (≈2700 cm −1 ) peak positions for a CVD graphene film is due to hole doping effect with the transfer process . The graphene/hBN/n‐GaN heterostructure was used to fabricate a MIS based SBD and device properties were investigated.…”

Formation of Effective CuI‐GaN Heterojunction with Excellent Ultraviolet Photoresponsive Photovoltage

“…Figure b shows the Raman spectra for a γ‐CuI/GaN heterostructure. The peak at 130 cm −1 corresponds to γ‐CuI and the peaks at higher wavenumbers 578 and 747 cm −1 correspond to the GaN film …”

“…Gallium nitride (GaN), a group III‐nitride compound semiconductor, with a wide band gap of 3.4 eV possesses excellent electronic properties and has been most widely researched for various device applications . Because of its several outstanding properties such as direct band gap, high critical breakdown field, and high electron saturation velocity, GaN has found many applications in light‐emitting diodes (LEDs), high electron mobility transistors, solar cells, and photodiodes .…”

“…Heterostructures have been used for optoelectronics, nanoelectronics, photocatalysis, and various other applications to overcome the shortcomings of single or monostructure materials . Recently, graphene and transition metal dichalcogenides (TMDCs) layers were combined with GaN to develop VdWs heterostructure devices . Graphene with a zero band gap forms a Schottky junction with GaN, whereas TMDCs with a direct band gap in the visible range create p‐n and n‐n + heterojunctions .…”

“…Recently, graphene and transition metal dichalcogenides (TMDCs) layers were combined with GaN to develop VdWs heterostructure devices . Graphene with a zero band gap forms a Schottky junction with GaN, whereas TMDCs with a direct band gap in the visible range create p‐n and n‐n + heterojunctions . In this prospect, a highly p‐type wide band gap semiconductor can be significant to develop a VdWs heterostructure with GaN.…”