本文推导了一种可简便、准确、直观计算和分析pn结I–V特性的公式和方法，并应 用该方法对两类典型HgCdTe环孔pn结的I–V、RD–V特性进行了计算和拟合；得到了表面欧姆(反型沟道)漏 电导、二极管理想因子n随电压的分布等反映二极管结特性的重要参数。计算结果表明，对于长波HgCdTe 光伏器件而言，表面漏电流在整个暗电流中所占的比重相当大，表面漏电流严重地制约着器件性能。HgCdTe 材料的晶体缺陷会使二极管的理想因子n增大，从而使产生–复合电流及陷阱辅助隧穿电流增加。

In this paper, a simple, accurate and intuitionistic formula and method for calculating and analyzing the I–V characteristics of a pn junction is deduced. The method is used to calculate and analyze the I-V and RD–V characteristics of two typical HgCdTe loophole junctions. Some important parameters which reflect the characteristics of a diode, such as surface Ohm leakage conductance and the distribution of the ideal factor n with voltage are obtained. The calculation result shows that for a long wavelength HgCdTe photovoltaic device, the surface leakage current accounts for a significantly large amount of the total dark current and imposes a severe restriction on the performance of the device. Due to the crystal defect in HgCdTe material, the ideal factor n of the diode can be increased and hence both the generation-recombination current and the trap-assisted tunneling current can be increased.