Fermi-level depinning at metal/GaN interface by an insulating barrier

Adari, R.; Banerjee, Debashree; Ganguly, Swaroop

doi:10.1016/j.tsf.2013.11.041

Cited by 11 publications

(8 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As an alternative passivation material with low interface states, AlN has been considered for GaN-based devices due to its smaller lattice mismatch to GaN [ 20 , 21 ]. In addition, modulation of electrical properties such as barrier heights in metal/semiconductor (MS) contacts by inserting very thin oxide layer has been reported in GaN [ 22 , 23 ]. Increase of the barrier height in Pt/HfO 2 /GaN metal-insulator-semiconductor (MIS) diodes with a 5-nm-thick HfO 2 layer was reported [ 22 ].…”

Section: Introductionmentioning

confidence: 99%

“…Increase of the barrier height in Pt/HfO 2 /GaN metal-insulator-semiconductor (MIS) diodes with a 5-nm-thick HfO 2 layer was reported [ 22 ]. Insertion of a 3-nm MgO layer at a Fe/GaN interface was found to reduce the effective barrier height to 0.4 eV [ 23 ]. Still now, however, there is limited number of papers reporting on the engineered contact properties with ALD-grown AlN on GaN.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thickness Dependence on Interfacial and Electrical Properties in Atomic Layer Deposited AlN on c-plane GaN

2018

View full text Add to dashboard Cite

The interfacial and electrical properties of atomic layer deposited AlN on n-GaN with different AlN thicknesses were investigated. According to capacitance–voltage (C–V) characteristics, the sample with a 7.4-nm-thick AlN showed the highest interface and oxide trap densities. When the AlN thickness was 0.7 nm, X-ray photoelectron spectroscopy (XPS) spectra showed the dominant peak associated with Al–O bonds, along with no clear AlN peak. The amount of remained oxygen atoms near the GaN surface was found to decrease for the thicker AlN. However, many oxygen atoms were present across the AlN layer, provided the oxygen-related defects, which eventually increased the interface state density. The barrier inhomogeneity with thermionic emission (TE) model was appropriate to explain the forward bias current for the sample with a 7.4-nm-thick AlN, which was not proper for the sample with a 0.7-nm-thick AlN. The reverse leakage currents for both the samples with 0.7- and 7.4-nm-thick AlN were explained better using Fowler–Nordheim (FN) rather than Poole–Frenkel emissions.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Thickness Dependence on Interfacial and Electrical Properties in Atomic Layer Deposited AlN on c-plane GaN

2018

View full text Add to dashboard Cite

show abstract

“…Another method that can de‐pin the Fermi level is to physically separate the metal and c‐ Si by introducing a thin interlayer (typically dielectrics), 15–17 as shown in Figure 1C. Particularly, the interlayer can passivate the c ‐Si surface through chemical passivation (e.g., saturating the dangling bonds) and field‐effect passivation (e.g., introducing net fixed charges) 18 .…”

Section: Introductionmentioning

confidence: 99%

Dopant‐free passivating contacts for crystalline silicon solar cells: Progress and prospects

Wang

Zhang

et al. 2022

EcoMat

View full text Add to dashboard Cite

The evolution of the contact scheme has driven the technology revolution of crystalline silicon (c-Si) solar cells. The state-of-the-art high-efficiency c-Si solar cells such as silicon heterojunction (SHJ) and tunnel oxide passivated contact (TOPCon) solar cells are featured with passivating contacts based on doped Si thin films, which induce parasitic optical absorption loss and require capitalintensive deposition processes involving flammable and toxic gasses. A promising solution to tackle this problem is to employ dopant-free passivating contact, involving the use of transparent and cost-effective wide band gap materials. In this review, we first introduce the dopant-free passivating contact, from carrier transport mechanisms, material classification to evaluation methods. Then we focus on the advances in different strategies to improve cell performance, including material property optimization, structural and interfacial engineering, as well as various post-treatments. At the end, the challenge and perspective of dopant-free passivating contact c-Si solar cells are discussed.

show abstract

“…GaN is a suitable semiconductor for investigating changes in the SBH because of its wide gap, leading to a large change in the current–voltage characteristics if such a change is possible. However, the insertion of an insulating layer at a metal/GaN interface has only been carried out for Fe and Fe/Gd electrodes, without any results for the metal‐work‐function dependence of the SBH, using GaN layers on sapphire substrates. A GaN epitaxial layer on a GaN freestanding substrate is characterized by a low defect density, which leads to excellent rectifying characteristics .…”

Section: Introductionmentioning

confidence: 99%

“…Recently, several publications have reported that the insertion of an ultrathin insulating layer led to a modification of the SBH for Si, Ge, GaAs, InGaAs, and GaN (on sapphire) . The initial explanation for this was that the inserted ultrathin interlayer prevents the generation of metal‐induced gap states (MIGS) by blocking the metal wave function acting as a tunnel barrier without disturbing the current flow because of its thinness, resulting in depinning .…”

Section: Introductionmentioning

confidence: 99%

Effect of Insertion of Ultrathin Al₂O₃ Interlayer at Metal/GaN Interfaces

Akazawa

Hasezaki

2017

Physica Status Solidi (b)

View full text Add to dashboard Cite

Fermi level depinning at a metal/semiconductor interface by using an ultrathin insulating interlayer to block the penetration of the metal wave function into the semiconductor is examined on GaN. A Si‐doped n‐type GaN epitaxial layer on a freestanding GaN substrate is used as the host material. For the samples with an interlayer, an ultrathin Al2O3 layer of 1 nm thickness is deposited by atomic layer deposition. As the metal layers, Ag, Cu, Au, Ni, and Pt are deposited by electron beam evaporation. Samples without an interlayer are also fabricated for comparison. The apparent change in current–voltage characteristics of the Schottky barrier diodes with the insertion of the interlayer is dependent on the electrode metal. However, the apparent Schottky barrier height (SBH) for the samples with the interlayer is almost constant and independent of the metal electrode, although the samples without an interlayer exhibit a moderate dependence of the SBH on the metal work function. Thus, the pinning becomes stronger upon the insertion of the interlayer, although blocking of the metal wave function by using an ultrathin insulator is expected to lead to depinning.

show abstract

Fermi-level depinning at metal/GaN interface by an insulating barrier

Cited by 11 publications

References 21 publications

Thickness Dependence on Interfacial and Electrical Properties in Atomic Layer Deposited AlN on c-plane GaN

Thickness Dependence on Interfacial and Electrical Properties in Atomic Layer Deposited AlN on c-plane GaN

Dopant‐free passivating contacts for crystalline silicon solar cells: Progress and prospects

Effect of Insertion of Ultrathin Al₂O₃ Interlayer at Metal/GaN Interfaces

Contact Info

Product

Resources

About

Fermi-level depinning at metal/GaN interface by an insulating barrier

Cited by 11 publications

References 21 publications

Thickness Dependence on Interfacial and Electrical Properties in Atomic Layer Deposited AlN on c-plane GaN

Thickness Dependence on Interfacial and Electrical Properties in Atomic Layer Deposited AlN on c-plane GaN

Dopant‐free passivating contacts for crystalline silicon solar cells: Progress and prospects

Effect of Insertion of Ultrathin Al2O3 Interlayer at Metal/GaN Interfaces

Contact Info

Product

Resources

About

Effect of Insertion of Ultrathin Al₂O₃ Interlayer at Metal/GaN Interfaces