Silicon-carbide (SiC) is the semiconductor material with properties which make it suitable for radiation detection. Wide band gap, small intrinsic carrier concentration, small leakage current, large breakdown voltage, good thermal conductivity, hardness, excellent resistance to large temperatures and high radiation tolerance are all properties which make it better than silicon - the most widely used material in semiconductor detectors. First of all, in this paper is made the comparison between transport properties of Si and 4H-SiC, which have similar dopance and dimensions. The experimental methods which are used are temperature dependent current-voltage (I-V) and capacitance-voltage (C-V) measurements, with the purpose to get the parameters which are important for detectors, and to recognize dominant transport mechanisms. 4H-SiC SBD has shown much less leakage current, the smaller temperature dependence of depletion region width and of free carrier concentration, the smaller series resistance and also recombination-generation (RG) current in depletion region is negligible. All this is the indicator of a better energy resolution and time resolution, but also of the higher temperature stability in 4H-SiC detector. Two 4H-SiC diodes are irradiated with thermal and fast reactor neutrons to see their effect on transport properties. All of the observed changes point to the introduced interface states that locally influence Schottky barrier height. Fast neutrons have introduced much more concentration of such defects than thermal neutrons. Other paramethers that directly affect the detection properties have shown negligible change after the irradiation. Finnaly, a different detector structure has been studied – MOS (metal-oxide-semiconductor), where I-V and C-V characterisation have been made on the unirradiated Si/SiO2 MOS and on the sample irradiated with fast neutrons. In the irradiated sample defects introduced to the oxide and the oxide-semiconductor interface have been observed.