As compared with single-stage thermoelectric coolers (TECs), two-stage TECs can achieve a larger temperature drop when TECs operate at steady state conditions. In this work, pulse currents are respectively supplied to the hot and the cold stage of a two-stage cascaded TEC to seek further increase in temperature drop across the TEC. The results show that the two-stage TEC yields a lower cold end temperature and a longer holding time of supercooling state than the single-stage counterpart. The minimum cold end temperature, T-c,T-min, can be further improved by the matching between the pulse amplitude and width on the cold stage (P-c and tau(c)) and the pulse amplitude and width on the hot stage (P-h and tau(h)). When P-c and tau(c) are specified, the same P-h (=P-c) and a shorter tau(h) (

Keywords:Two-stage thermoelectric cooler;Transient supercooling;Separate current pulse;Cold end temperature;Holding time