Electrical transport measurements and emission properties of freestanding single crystalline CVD diamond samples

Abstract

In this work time-of-flight (TOF) measurements are performed on freestanding single crystalline (100) CVD diamond layers with different surface terminations. The transit properties and electron and hole mobility are measured for completely oxidised and completely hydrogenated diamonds. The results clearly show that the different terminations of the diamond surface have an influence on the electrical transport properties. Furthermore, evidence is given that oxygen-induced surface states influence the TOF spectra. Light emission at 235 nm and around 430 nm is observed when applying a pulsed electric field on the diamond. The small peak at 235 nm, is attributed to free exciton recombination while the broad band at 430 nm is contributed to A-band luminescence. Emission spectra at voltages as high as 1.4 V/mu m are given and compared. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.