Introduction Cadmium manganese telluride (Cd1-xMnxTe, CMT) is an ideal material for room-temperature radiation detectors, which can be widely used in the fields of medical tests, radiation detection, and astrophysics. The higher partial pressure of Cd during the growth of CMT single crystals by the Bridgman method leads to severe volatilization of Cd, which in turn produces a high density of intrinsic point defects, such as Cd vacancies. This reduces the resistivity of the crystal and alters the conductive type of the crystal, making it difficult for the crystal to meet the requirements for device preparation. In this paper, CMT crystals were grown by a vertical Bridgman method with Te solution. The compositions were co-doped with In/V at 1017 atom/cm3 to compensate for the Cd vacancies and increase the crystal resistivity.In addition, the electrical properties of Au, Ag, Al and In electrodes in contact with CMT semiconductors were also investigated.Methods Te (9N), Cd (9N), In (9N), Mn (5N), and V (5N) were used as raw materials in a pellet form (Sichuan Ehalf High Purity Materials Co., China). Cd0.9Mn0.1Te single crystals co-doped with In and V (doping concentrations of 2×1017 atom/cm3 and 3×1017 atom/cm3, respectively) were grown by a vertical Bridgman method with Te solution. The grown ingots were 95 mm in length and 30 mm in diameter, and a diamond wire cutting machine was used to cut wafers with a thickness of 2 mm at the head, middle and tail of Cd0.9Mn0.1Te:In/V ingots, and further cut single crystals of 10 mm×10 mm×2 mm. The head, middle and tail single crystals of Cd0.9Mn0.1Te:In/V ingots were tested for the crystal structure by a model D/M-2500 X-ray diffractometer, respectively. The optical properties of crystals were determined by Fourier transform infrared spectroscopy and UV-visible-near-infrared spectroscopy. Four single-crystal samples in the middle of Cd0.9Mn0.1Te:In/V ingot were selected as CMT detector materials. Au, Ag, Al and In metal electrodes were deposited on the surface of the crystals by a model KYKY-SBC-21 vacuum evaporation machine. The four metals were deposited by using 4N-grade high-purity evaporation wires with a diameter of 0.5 mm and a length of 80 mm. In order to ensure a low background noise in the detector, a low leakage current of the crystal was required and the electrodes were passivated with hydrogen peroxide after preparation. Au and In electrode CMT detectors were annealed in a model OTF-1200X tubular annealing furnace at different temperatures (i.e., 350, 370, 390, 410 K and 430 K) for 1 h, respectively. The electrical performance of CMT detectors with different electrodes was tested by a model agilent model 4155c semiconductor parameter analyzer.Results and discussion Cd0.9Mn0.1Te:In/V single crystal is a crystal structure of sphalerite, in which the diffraction peak (111) has the maximum intensity, indicating that the preferred crystal growth direction is the direction (111). The average IR transmittance of the single crystal in the middle of the ingot is 67.3%, which is the maximum value reported in the literature. The high IR transmittance of In and V co-doped Cd0.9Mn0.1Te crystals is attributed to the fact that the double dopant adequately compensates for the acceptor defect Cd vacancies and reduces the vacancy defect concentration.The average roughness of Ag, Ag, Al and In electrodes deposited on the surface of CMT crystals are all below 20 nm. Based on the results of electrical performance tests, the ohmic coefficient of Au electrode is close to 1, and the ohmic contact performance of Al and Ag electrodes is poorer. The adaptability of different materials to the annealing temperature is different, the leakage current of Au electrode decreases as the annealing temperature increases to 390 K. The leakage current of In electrode decreases only slightly after annealing at 350 K, and the leakage current of In electrode is greater than that of the unannealed one after annealing at >370 K, indicating that there is a limitation of annealing on the improvement of the electrical properties of the In electrode.Conclusions The forbidden band width of Cd0.9Mn0.1Te:In/V single crystal was 1.52 eV, and the IR transmittance of the middle crystal was 67.3%, indicating that the middle crystal had superior optical properties. Al, Ag, In and Au electrode materials all formed ohmic contacts with the CMT, with the optimum electrical performance of Au and In electrodes. The optimum annealing temperatures for Au and In electrodes were 390 K and 350 K. Au and In electrodes were annealed at 390 K and 350 K, respectively. Au could be the most suitable electrode material for Cd0.9Mn0.1Te:In/V single-crystal radiation detectors.