Characterization of electronic properties of natural type IIb diamonds

Abstract

Precision admittance spectroscopy measurements were carried out over wide temperature and frequency ranges for a set of natural single crystal type IIb diamond samples. Peaks of conductance spectra vs. temperature and frequency were used to compute the Arrhenius plots, and activation energies were derived from these plots. The capacitance-voltage profiling was used to estimate the majority charge carrier concentration and its distribution into depth of the samples. Apparent activation energies between 315 and 325 meV and the capture cross section of about 10 -13 cm 2 were found for samples with uncompensated boron concentrations in the range of 1 to 5 x 10 16 cm -3 (0.06-0.3 ppm). The obtained boron concentrations are in good coincidence with FTIR results for the samples. Also, the reason the difference between the observed admittance activation energy and the previously reported ionization energy for the acceptor boron in diamond (0.37 eV) is proposed. Graphical abstract Highlights Admittance spectroscopy is a powerful and nondestructive technique, which allows one to obtain characteristics of electronic spectra for doped diamonds  The combination of temperature and frequency admittance spectra give the convenient and tunable set of tools for the comprehensive analysis of impurity and defect levels, their activation energies and capture cross sections  For the first time the activation energy and the capture cross section for boron deep center in natural diamond was obtained by admittance spectroscopy with high precision: for all natural "blue" diamonds (type IIb) the apparent activation energy is 315-325 meV, with the mean square error (MSE) for every sample no more than 1-2 meV. The reasons for the difference with the optical ionization energy is discussed

Carrier concentration variety over multisectoral boron-doped HPHT diamond

“…The software includes a system of embedded cycles allowing accurate control of experiment parameters (temperature and its change rate, test signal frequency, AC and DC biases, the amount of averaging) and mathematical processing of the acquired data. The complex allows recording admittance spectra with temperature and frequency sweep, current-voltage and capacitance-voltage characteristics, Cole-Cole plots [21,22]. Measurements are performed in wide temperature (20 K to 450 K) and frequency (20 Hz to 2 MHz) ranges.…”

Характеризация Электрофизическими Методами Монокристаллического Алмаза, Легированного Бором (Обзор)

“…Нами в работах [84,132,133] Кроме переменного тестового сигнала, имеется другой источник неоднозначности измерений. В спектроскопии адмиттанса к традиционным объемным полупроводникам не прикладывается смещение, поскольку от него результат измерений не зависит [135].…”

Characterization of boron-doped single-crystal diamond by electrophysical methods (review)

“…In the works [84,132,133] we have for the first time performed a systematic cycle of the admittance measurements on the samples of boron-doped single-crystal diamond. The admittance spectra of the weakly-doped diamond samples with the boron concentration N A = (2−5) • 10 16 cm −3 , which are measured at the alternating (AC) test signal, give the typical activation energy of the boron acceptor level within the range from 285 to 325 meV [133].…”