Single crystal growth and photoconductivity of the layered materials MnIn2SxSe4-x

Single crystals of MnIn2SxSe4-x with 0.4 ≤ × ≤ 2.4 have been obtained by chemical transport reactions with iodine in the temperature gradient 860 → 800 °C. Ohmic contacts to these crystals could be obtained by treatment of the crystals with hydrogen and/or indium at 400 °C. By this treatment the conductivity of the crystals, which are very poor conductors in the untreated state, are enhanced by at least 6 orders of magnitude. The samples are photoconductors with a photo sensitivity S = (σp−σd)/σd between 1 and 10−4, depending on the treatment of the crystals.