ELECTROTHERMAL INVESTIGATION OF THE SWITCHING PHENOMENA IN P-TYPE TLINSE2 SINGLE-CRYSTALS

Large TlInSe2 single crystals are grown by the Bridgman-Stockbarger me thod, starting from stoichiometric melts. Current-voltage (I-V) charac teristics of symmetric In/p-TlInSe2/In structures exhibit two distinct regions: an ohmic region at low current densities and a non-linear re gion (S-shaped) having negative differential resistance (NDR) at moder ate and higher current densities. An electrothermal model is used for the explanation of this non-linear behaviour. The non-linear behaviour of the I-V curves is studied at different ambient temperatures in the 100 to 340 K region. The sample temperature and the threshold voltage of the NDR region are examined as a function of current density and a mbient temperature, respectively. The electrothermal model is quite sa tisfactory for the explanation of this process.