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大电流下双极晶体管的种种行为,必须得到详尽的解释。到目前为止,虽对此已提出过许多大同小异的方案,但人们普遍认为:仅从研究物理现象所用的方法,以及满足分析式所确立的边界条件等方面。就可以看出,这些研究是不完备的。本文在考察发射极-基极结中载流子的能量分布的基础上,在指出了采用通常的密度扩散方程中的谬误的同时,从理论上说明了各种偏压条件下,双极晶体管的电流由小到大的内部工作状态。我们虽然也按照定在所采用的定差法进行数值分析,在确立基区两端的边界条件上和原来完全不同。即(1)在发射区一侧,使空穴密度、电场,电位和发射区是连续的,有相当理由把电子密度和发射区修正成为是不连续的。(2)在集电极一侧,当电场达到饱和以后,注入载流子的扩散成份可以忽视,而且要使漂移速度也达到饱和。此外不仅要考虑载流子迁移率与电场的依赖关系,同时也要考虑扩散系数与电场的关系。还要把热效应都考虑进去。其结论是我们不仅把双极晶体管的电流电压工作点和内部工作状态——对应起来,同时还对若干实验数据做了比较研究。
The behavior of bipolar transistors at high currents must be explained in detail. So far, many similar proposals have been made for this purpose, but it is generally accepted that only the methods used to study physical phenomena and the boundary conditions established by analytical expressions are satisfied. As you can see, these studies are incomplete. Based on the investigation of the energy distribution of carriers in the emitter-base junction, the paper not only points out the fallacies in the usual density diffusion equation, but also theoretically shows that under various bias conditions, the bipolar transistor The current from small to large internal working condition. Although we also carry out numerical analysis according to the fixed difference method adopted, we are completely different from the original one in establishing the boundary conditions at both ends of the base area. That is, (1) there is a reason to correct the electron density and emitter region discontinuities for the reason that the hole density, the electric field, the potential and the emitter region are continuous on the emitter side. (2) On the collector side, when the electric field is saturated, the diffusion of injected carriers can be neglected, and the drift speed is also saturated. In addition, it is necessary to consider not only the dependence of the carrier mobility on the electric field, but also the relationship between the diffusion coefficient and the electric field. Also take into account the thermal effects. The conclusion is that we not only put the bipolar transistor current and voltage operating point and the internal working state - corresponding, but also a number of experimental data to do a comparative study.