论文部分内容阅读
为了研究有机半导体材料的载流子传输特性,制备了单层器件ITO/NPB/Ag,建立了该器件的理论导纳模型.利用正弦小信号频域测试法得到该器件在不同直流偏压下的频率特性样本.定义了同时包含有机半导体阻抗实部和虚部的模型参数辨识问题的目标函数,采用粒子群算法对包括载流子迁移时间τdc,色散度参数M和α在内的模型参数进行辨识.为了验证提出方法的有效性,建立了器件的等效电路模型,并用最小二乘算法辨识出等效电路的时间常数τc.实验上对1000 nm和1200 nm的单层器件进行频域测试,经计算发现τdc和τc之间具有相同的比例关系,通过对计算出的空穴迁移率μdc进行指数拟合发现,两种厚度的NPB器件的空穴迁移率与电场强度呈指数增加,且满足著名的Poole-Frenkel公式.
In order to study the carrier transport characteristics of organic semiconductors, single-layer device ITO / NPB / Ag was prepared and the theoretical admittance model of the device was established.Using sinusoidal small-signal frequency domain test, The objective function of model parameters identification including real part and imaginary part of the impedance of organic semiconductors is defined. Particle swarm optimization algorithm is applied to model parameters including carrier migration time τdc, dispersion parameters M and α In order to verify the effectiveness of the proposed method, the equivalent circuit model of the device is established and the time constant τc of the equivalent circuit is identified by the least-squares algorithm.Experiments on the single-layer device at 1000 nm and 1200 nm are performed in the frequency domain The results show that there is the same ratio between τdc and τc. By exponentially fitting the calculated hole mobility μdc, the hole mobility and the electric field strength of two kinds of NPB devices increase exponentially, And meet the famous Poole-Frenkel formula.