The Hydrogenation Impact on Electronic Properties of p-Diamond/n-Si Heterojunctions

Stability Study of Synthetic Diamond Using a Thermally Controlled Biological Environment: Application towards Long-Lasting Neural Prostheses

This paper demonstrates, for the first time, the stability of synthetic diamond as a passive layer within neural implants. Leveraging the exceptional biocompatibility of intrinsic nanocrystalline diamond, a comprehensive review of material aging analysis in the context of in-vivo implants is provided. This work is based on electric impedance monitoring through the formulation of an analytical model that scrutinizes essential parameters such as the deposited metal resistivity, insulation between conductors, changes in electrode geometry, and leakage currents. The evolution of these parameters takes place over an equivalent period of approximately 10 years. The analytical model, focusing on a fractional capacitor, provides nuanced insights into the surface conductivity variation. A comparative study is performed between a classical polymer material (SU8) and synthetic diamond. Samples subjected to dynamic impedance analysis reveal distinctive patterns over time, characterized by their physical degradation. The results highlight the very high stability of diamond, suggesting promise for the electrode's enduring viability. To support this analysis, microscopic and optical measurements conclude the paper and confirm the high stability of diamond and its strong potential as a material for neural implants with long-life use.

A Review on Optoelectronical Properties of Non-Metal Oxide/Diamond-Based p-n Heterojunction

Diamond holds promise for optoelectronic devices working in high-frequency, high-power and high-temperature environments, for example in some aspect of nuclear energetics industry processing and aerospace due to its wide bandgap (5.5 eV), ultimate thermal conductivity, high-pressure resistance, high radio frequency and high chemical stability. In the last several years, p-type B-doped diamond (BDD) has been fabricated to heterojunctions with all kinds of non-metal oxide (AlN, GaN, Si and carbon-based semiconductors) to form heterojunctions, which may be widely utilized in various optoelectronic device technology. This article discusses the application of diamond-based heterostructures and mainly writes about optoelectronic device fabrication, optoelectronic performance research, LEDs, photodetectors, and high-electron mobility transistor (HEMT) device applications based on diamond non-metal oxide (AlN, GaN, Si and carbon-based semiconductor) heterojunction. The discussion in this paper will provide a new scheme for the improvement of high-temperature diamond-based optoelectronics.

The Barrier's Heights and Its Inhomogeneities on Diamond Silicon Interfaces

In this work, the electrical parameters of the polycrystalline diamonds' p-PCD/n-Si heterojunction were investigated using temperature-dependent current-voltage (I-V) characteristics. In the temperature range of 80-280 K, the ideality factor (n) and energy barrier height (φb) were found to be strongly temperature dependent. The φb increases with temperature rise, while the n value decreases. The observed dependencies are due to imperfections at the interface region of a heterojunction and the non-homogeneous distribution of the potential barrier heights. Values of the φb were calculated from I-V characteristics using the thermionic emission theory (TE). The plot of φb versus 1/2 kT revealed two distinct linear regions with different slopes in temperature regions of 80-170 K and 170-280 K. This indicates the existence of a double Gaussian distribution (DGD) in heterojunctions. Parameters such as mean barrier heights φ¯b and standard deviations σ were obtained from the plots linearization and read out from intercepts and slopes. They take values φ¯b = 1.06 eV, σ = 0.43 eV, respectively. The modified Richardson plot is drawn to show the linear behavior in these two temperature ranges, disclosing different values of the effective Richardson constants (A*).