Thermoelectric power of nitrogen-incorporated tetrahedral amorphous-carbon films

Abstract

Tetrahedral amorphous-carbon (ta-C) films were deposited using a filtered cathodic vacuum arc in which nitrogen was incorporated up to an atomic fraction (fN) of 30%. Electrical conductivity and specially thermoelectric power (S) have been performed over a wide range of temperature. The room-temperature conductivity of these samples initially increases with fN up to several orders of magnitude compared to that of ta-C, followed by no dramatic change at higher nitrogen concentration. The sign of the S is negative in the samples with fN below ∼17%, then changes to a positive value with a higher fN. From thermal annealing of the nitrogenated samples a change of the sign of S and its dependence on fN has been analyzed. The small values of both room-temperature S and small variation of conductivity at high fN in all the samples suggest that electrical properties of these films are controlled by compensation of defects.

Nitrogen doping of tetrahedral amorphous carbon films: Scanning tunneling spectroscopy

“…Films containing high percentage of nitrogen are found to be slightly p type. We are not certain about the reason behind 23 and think that it is due to compensation of defects. 24 In this article we describe the same characteristics of the sample independently from the information obtained from STS.…”

First-Principles Study of Nanodiamond Doped With B and N

“…4 On the other hand, nitrogen is known to be a successful (deep) donor in diamond. 5 The potential n-type dopants of diamond are of particular interest, since they can enhance the field-emission properties of disordered and nanocrystalline carbon films by providing electrons close to the conduction band 6,7 and helping to control the film microstructure by introducing specific types of defects. 8 The study of the dopants in nanocrystalline diamond is also important, since doped nanodiamonds have been suggested as candidates of qubits for quantum computing.…”

Photovoltaic Characteristics of Heterojunction Diode Comprising Boron-Doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Film and n-Type Silicon

“…Ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films, wherein nanosized diamond grains are embedded in an a-C:H matrix, contain a very large number of grain boundaries (GBs) in the films, which is a distinctive structure specific to UNCD/a-C:H films. The electrical properties of UNCD/a-C:H films, mainly prepared by chemical vapor deposition (CVD), have received considerable attention [1].…”