Role of additives and surface passivation on the performance of perovskite solar cells

Abstract

Outstanding improvement in power conversion efficiency (PCE) over 25% in a very short period and promising research developments to reach the theoretical PCE limit of single junction solar cells, 33%, enables organic–inorganic perovskite solar cells (OIPSCs) to gain much attention in the scientific and industrial community. The simplicity of production of OIPSCs from precursor solution either on rigid or flexible substrates makes them even more attractive for low-cost roll-to-roll production processes. Though OIPSCs show as such higher PCE with simple solution processing methods, there are still unresolved issues, while attempts are made to commercialize these solar cells. Among the major problems is the instability of the photoactive layer of OIPSCs at the interface of the charge transport layers and /or electrodes during prolonged exposure to moisture, heat and radiation. To achieve matched PCE and stability, several techniques such as molecular and interfacial engineering of components in OIPSCs have been applied. Moreover, in recent times, engineering on additives, solvents, surface passivation, and structural tuning have been developed to reduce defects and large grain boundaries from the surface and/or interface of organic–inorganic perovskite films. Under this review, we have shown recently developed additives and passivation strategies, which are strongly focused to enhance PCE and long-term stability simultaneously.

Assessing Performance and Limitations of a Device‐Level Machine Learning Approach for Perovskite Solar Cells with an Application to Hole Transport Materials

“…There are slight differences on the feature importance ranking emerging from the different models; nevertheless, there is a certain consistency given the fact that only 17 features show up in slightly different orders if the first 12 most significant features are independently selected for each model. In particular, there is consensus on the most impactful variable being HTL mobility (it is worth noting that this agrees with recent findings obtained using comparable techniques [ 54 ] ). It should be stressed that in Equation () the absolute value is taken; therefore, this feature importance ranking simply reflects how significantly, on average, the contribution of a given feature shifts the prediction from the base value (see Equation ()), regardless of the sign of the contribution.…”

Passivation Engineering Using Ultrahydrophobic Donor–π–Acceptor Organic Dye with Machine Learning Insights for Efficient and Stable Perovskite Solar Cells

“…This is in parallel with increased light harvesting and charge separation as well as enhanced charge carriers' extraction ability of the absorber layer. [46][47][48][49] A similar behavior was observed in the case of the FF, which apparently increased from 0.71 for the control up to 0.74 for the modified devices. The improved FF values may be linked to the optimization of the relevant interfaces and the reduction of the charge recombination process.…”

“…This is in parallel with increased light harvesting and charge separation as well as enhanced charge carriers’ extraction ability of the absorber layer. [ 46–49 ]…”

Molecular design for perovskite solar cells

“…Secondly, the additive molecules can be molecularly engineered to alter the resulting halide perovskite crystal structures, morphologies, and roughness; this is often accompanied with the formation of intermediate compounds in the precursor solution 76‐78 . Many molecular additives compatible with the halide perovskites are available, including those based on small organic molecules, fullerene polymers, and organometallic halide salts, which significantly influence the perovskite morphology and crystallization kinetics 79‐83 . The following aspects have been pointed out to effectively design the molecular additives for perovskite solar cells from the molecular engineering point of view.…”