The n–Si/p–CVD Diamond Heterojunction

Abstract

Due to the possible applications, materials with a wide energy gap are becoming objects of interest for researchers and engineers. In this context, the polycrystalline diamond layers grown by CVD methods on silicon substrates seem to be a promising material for engineering sensing devices. The proper tuning of the deposition parameters allows us to develop the diamond layers with varying crystallinity and defect structure, as was shown by SEM and Raman spectroscopy investigations. The cathodoluminescence (CL) spectroscopy revealed defects located just in the middle of the energy gap of diamonds. The current–voltage–temperature, I−V−T characteristics performed in a broad temperature range of 77–500 K yielded useful information about the electrical conduction in this interesting material. The recorded I−V−T in the forward configuration of the n–Si/p–CVD diamond heterojunction indicated hopping trough defects as the primary mechanism limiting conduction properties. The Ohmic character of the carriers flux permitting throughout heterojunction is intensified by charges released from the depletion layer. The magnification amplitude depends on both the defect density and the probability that biasing voltage is higher than the potential barrier binding the charge. In the present work, a simple model is proposed that describes I−V−T characteristics in a wide range of voltage, even where the current saturation effect occurs.

The Undoped Polycrystalline Diamond Film—Electrical Transport Properties

“…Below specific characteristic temperature of 200 K in our case, the transport properties changes so much that the law of carrier’s concentration is no longer valid. In our opinion, one model describing whole temperature dependence is still beyond the knowledge, due to substantial difference observation of ln dependence versus temperature [ 19 ] instead of reciprocal temperature. Although, the low temperature carrier’s transport mechanism can be analyzed by using of the Mott Variable Range Hopping (M-VRH) if the Coulomb interactions are neglected or Efros-Shklovskii (ES-VRH) models if the long-range Coulomb interaction is taken into account [ 41 , 42 , 43 ].…”

“…The most effective method to characterize the electronic properties of semiconductor materials is to study the mechanisms of electrical transport. In particular, the conductivity measurements (I-V-T) [ 19 ] as a function of temperature provide valuable information about the conduction mechanisms and parameters such as charge-carrier density, mobility, and defect ionization energy. J-V-T characteristics for diamond were also analysed by A.M. Rodrigues, et al and J.C. Madaleno et.…”

Orientation Dependence of Cathodoluminescence and Photoluminescence Spectroscopy of Defects in Chemical-Vapor-Deposited Diamond Microcrystal

“…The defects restrict phonons' free path or their lifetime, the length of which is proportional to the reciprocal value of the FWHM. According to the following simple relation [32] FW HM × L = 90 (cm −1 nm)…”