Homoepitaxial growth and n-type impurity doping of CdTe layers at low substrate temperatures were carried out for their applications in nuclear radiation detector fabrication. The grown epilayers were characterized by scanning electron microscopy, photoluminescence and Hall measurements. Highly conductive iodine doped layers could be obtained at a substrate temperature of 150 C, and these layers were found to be more suitable for radiation detector applications than other layers grown at higher substrate temperatures. The surface morphology of these homoepilayers was not very smooth, however, distinct edge emission and deep level emission bands were observed on the PL spectra at 20 K. A diode-type radiation detector fabricated using this low temperature growth and doping technique, exhibited very good rectification property with a very low value of reverse bias leakage current and an excellent nuclear radiation detection property.Introduction CdTe is a technologically important semiconductor with its applications in nuclear radiation detectors, infrared detectors, solar cells, and other optoelectronic devices, and has long been investigated [1,2]. Many device applications require low temperature growth and efficient substitutional doping with donor and/or acceptor. Particularly in the nuclear radiation detector fabrication, low device leakage current is an essential factor because it allows one to apply high electric field on the detector which, in turn, improves the charge transport properties and hence the detector performance. However, the maximum resistivity of the detector grade crystal available today is in the order of 10 9 Wcm and it suffers from excessive leakage current when a high electric field is applied on the detector. Fabricating a rectifying junction on the crystal wafer by growing an epitaxial layer on the crystal helps to suppress the leakage current significantly. However, the lack of a low temperature growth and doping technique has limited this approach because there is a possibility of initial crystal degradation at high temperature growth as the CdTe crystals are vulnerable to high temperature processing [3].We have used a remote-plasma-assisted MOCVD system for the epitaxial growth and doping of CdTe at low substrate temperature. This system has been assisted with atomic-hydrogen radicals produced in a remote plasma zone. These plasma radicals help to enhance the decomposition of source monomers and result an epitaxial growth even at low substrate temperatures. Properties of the grown epilayers doped with iodine for ntype impurity will be presented. Furthermore, performance of a diode-type nuclear ra-