arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1708.09210physics.app-ph
收藏

平板型钙钛矿太阳电池表面极化模型的系统推导

Systematic derivation of a surface polarization model for planar perovskite solar cells

N. E. Courtier, J. M. Foster, S. E. J. O'Kane, A. B. Walker, G. Richardson

摘要:

越来越多的证据表明,钙钛矿太阳能电池中移动离子的存在会导致电流-电压曲线滞后。采用漂移扩散模型分析了平面金属卤化物CH $_3$ NH $_3$ PbI $_3$钙钛矿太阳能电池的稳态和瞬态电流-电压特性。钙钛矿层内的高离子空位密度产生窄的德拜层(典型宽度$\sim$ 2nm),其邻近于与传输层的界面,在其上发生电势的大的下降,并且在其中存储有显著的电荷。(I)德拜层的宽度和钙钛矿层的宽度($\sim$ 600 nm)与(II)离子空位密度和载流子密度之间的大差异激发了求解模型的渐近方法,而方程的刚性使得标准解方法不可靠。我们推导出一个简化的表面极化模型,在该模型中,慢离子动力学被替换为在钙钛矿界面的界面(非线性)电容。Favourable比较的结果之间的渐近方法和数值解的一个现实的细胞在广泛的操作条件下的实际利益。

英文摘要:

Increasing evidence suggests that the presence of mobile ions in perovskite solar cells can cause a current-voltage curve hysteresis. Steady state and transient current-voltage characteristics of a planar metal halide CH$_3$NH$_3$PbI$_3$ perovskite solar cell are analysed with a drift-diffusion model that accounts for both charge transport and ion vacancy motion. The high ion vacancy density within the perovskite layer gives rise to narrow Debye layers (typical width $\sim$2nm), adjacent to the interfaces with the transport layers, over which large drops in the electric potential occur and in which significant charge is stored. Large disparities between (I) the width of the Debye layers and that of the perovskite layer ($\sim$600nm) and (II) the ion vacancy density and the charge carrier densities motivate an asymptotic approach to solving the model, while the stiffness of the equations renders standard solution methods unreliable. We derive a simplified surface polarisation model in which the slow ion dynamic are replaced by interfacial (nonlinear) capacitances at the perovskite interfaces. Favourable comparison is made between the results of the asymptotic approach and numerical solutions for a realistic cell over a wide range of operating conditions of practical interest.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑