Abstract: To enhance the high voltage and high current handling capacity of bipolar charge plasma transistor (BCPT), a device model of npn BCPT was established by SILVACO TCAD for balancing high current gain β, high breakdown voltage of collector junction with emitter open V_CBO and high breakdown voltage of collector and emitter with base open V_CEO. Considering that the breakdown voltage of bipolar transistors depends mainly on the doping concentration of the collector, the influence of collector metal on the performance of BCPT was firstly studied. It is shown that the collector electron concentration of BCPT depends strongly on the work function of the electrode metal. When aluminum (Al) with a larger work function is adopted as the collector electrode metal, the concentration of electron plasma induced in the collector region is reduced due to the decrease of work function difference between the metal and semiconductor contact. As a result, the peak electric field in the space charge region of the collector is reduced effectively, and the peak electron temperature and the peak electron impact ionization rate are also reduced, which leads to the improvements of the breakdown voltage V_CBO and V_CEO. However, a decrease of electron concentration in collector will cause the Kirk effect in base, which will increase base recombination and lead to the decrease of β. Therefore, a structure of BCPT with substrate bias was proposed, where the positive substrate bias was adopted underneath the emitter and base to modulate the effective carrier concentration for increasing the efficiency of emitter junction injection and the β. Results show that when compared with BCPT with zirconium (Zr) as collector metal, the peak value of β of the BCPT is improved by 21.69%, and both of the breakdown voltage V_CBO and V_CEO are improved by 12.78% and 56.41%, respectively, which effectively expands the high power application range of BCPT.