Department of Natural Sciences, Åbo Akademi University, Finland.
Phys Chem Chem Phys. 2012 Nov 7;14(41):14186-9. doi: 10.1039/c2cp41543g.
We have fabricated hybrid devices in the form of indium tin oxide/titanium dioxide/poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester/copper (ITO/TiO(2)/P3HT:PCBM/Cu) to clarify the impact of the TiO(2)/P3HT:PCBM interface on the charge transport using the charge extraction by linearly increasing voltage (CELIV) technique. We found that a large equilibrium charge reservoir is accumulated at negative offsets at the TiO(2)/P3HT:PCBM interface leading to space charge limited extraction current (SCLC) transients. We show analytically the SCLC transient response and compare the experimental data to calculated SCLC at a linearly increasing voltage. The theoretical calculations indicate that the large charge reservoir at negative offset voltages is due to thermally generated charges combined with poor hole extraction at the ITO/TiO(2) contact, due to the hole blocking character of TiO(2).
我们制备了氧化铟锡/二氧化钛/聚（3-己基噻吩）：[6,6]-苯基 C61 丁酸甲酯/铜（ITO/TiO 2 /P3HT：PCBM/Cu）的混合器件，以利用线性增加电压的电荷提取（CELIV）技术阐明 TiO 2 /P3HT：PCBM 界面对电荷输运的影响。我们发现，在 TiO 2 /P3HT：PCBM 界面处，在负偏置下会积累大量的平衡电荷储存库，从而导致空间电荷限制提取电流（SCLC）瞬变。我们分析了 SCLC 瞬态响应，并将实验数据与线性增加电压下的计算 SCLC 进行了比较。理论计算表明，在负偏压下的大电荷储存库是由于热产生的电荷以及 ITO/TiO 2 接触处的空穴提取不良所致，这是由于 TiO 2 的空穴阻挡特性所致。
