Device Physics of Hybrid Perovskite Solar cells: Theory and Experiment

Abstract

Perovskite solar cells (PSCs) exhibit a series of distinctive features in their optoelectronic response which have a crucial influence on the performance, particularly for long‐time response. Here, a survey of recent advances both in device simulation and optoelectronic and photovoltaic responses is provided, with the aim of comprehensively covering recent advances. Device simulations are included with clarifying discussions about the implications of classical drift–diffusion modeling and the inclusion of ionic charged layers near the outer carrier selective contacts. The outcomes of several transient techniques are summarized, along with the discussion of impedance and capacitive responses upon variation of bias voltage and irradiance level. In relation to the capacitive response, a discussion on the J–V curve hysteresis is also included. Although alternative models and explanations are included in the discussion, the review relies upon a key mechanism able to yield most of the rich experimental responses. Particularly for state‐of‐the‐art solar cells exhibiting efficiencies around or exceeding 20%, outer interfaces play a determining role on the PSC's performance. The ionic and electronic kinetics in the vicinity of the interfaces, coupled to surface recombination and carrier extraction mechanisms, should be carefully explored to progress further in performance enhancement.

Efficient Inverted Planar Perovskite Solar Cells Using Ultraviolet/Ozone‐Treated NiOx as the Hole Transport Layer

“…On one hand, the J SC of all PSCs based on UVO‐NiO x has been larger than 23 mA cm −2 , at least 7.8% higher than that of the control device. The optimal J SC can be up to 23.41 mA cm −2 , as far as we know, which is comparable to the published record (24.19 mA cm −2 ) in pure MAPbI 3 system, but still shows significant gap to the theoretical limit of MAPbI 3 ‐based PSCs (26.46 mA cm −2 ) . On the other hand, the V OC increment is related to the UVO exposure time.…”

Negative capacitance from the inductance of ferroelectric switching

“…Therefore, the electrical characteristics of ZrO 2 MFM structure can be described in terms of an equivalent circuit containing inductance [26][27][28][29][30] , confirming the presence of inductance in nano-f-ZrO 2 . Recently, the impedance behaviors of ferroelectric-like materials have been noticed in the metal-halide perovskite solar cells [31][32][33] , and their Nyquist plots are similar to that shown in Fig. 2c.…”

Stability and Dark Hysteresis Correlate in NiO‐Based Perovskite Solar Cells

“…In the whole protocol, no charge is extracted from the device, therefore, the decaying transient of the V oc is attributable to the internal recombination in the bulk of perovskite and at the interfaces with selective contacts. [67] As we report in Figure 5a,b, the introduction of MgO(R) led to a substantial increase of recombination lifetime, pointing to an improved quality of the NiO interface. In CE the device is kept at short circuit and, upon applying again a 2 µs light pulse (from the dark condition in this case), the photocurrent is recorded.…”