Quantifying Efficiency Loss of Perovskite Solar Cells by a Modified Detailed Balance Model

Abstract

mechanism and quantify the efficiency loss for perovskite solar cells.The analysis and quantification of efficiency loss of solar cells can be done by the drift-diffusion model, [24,25] circuit model, [26,27] and detailed balance model. [28,29] Due to a high nonlinearity of coupled equations and a complex device configuration, drift-diffusion model is difficult to retrieve simulation parameters from the measured current density-voltage (J-V) curves. The parameters include recombination rate, mobility, energy levels (e.g., conduction band, valence band, and work function), effective density of states, and injection/extraction barrier heights. Furthermore, the drift-diffusion model is nontrivial to describe the photon recycling effect correctly. [30] Concerning the circuit model, it requires to retrieve five parameters in modeling. Hence, the uniqueness of the parameters is questionable. Also, the ideality factor in the circuit model has ambiguous physical meaning and cannot quantitatively represent radiative recombination (photon recycling) and nonradiative (Auger and Shockley-Read-Hall) recombination separately. Additionally, while the traditional detailed balance model demonstrates a strong capability to predict the efficiency limit of an ideal solar cell, the model cannot quantify the energy loss of a practical solar cell including optical and electrical (thermodynamic) loss. In this work, a revised detailed balance model is proposed to unveil the loss mechanism and quantify the loss factors of perovskite solar cells. Through investigating the device performance of various fabricated perovskite solar cells, the three dominant loss factors of optical loss, nonradiative recombination loss, and ohmic loss are identified quantitatively. The perovskite-interface-induced surface recombination, ohmic loss, and current leakage are also analyzed. Consequently, the work offers a guideline to the researchers for optimizing perovskite solar cells and ultimately approaching the Shockley-Queisser limit of photovoltaics. [29] Results and Discussion TheoryIn order to understand the loss mechanism and qualify loss factors, we propose the revised detailed balance model, which is expressed as A modified detailed balance model is built to understand and quantify efficiency loss of perovskite solar cells. The modified model captures the light-absorption-dependent short-circuit current, contact and transport-layermodified carrier transport, as well as recombination and photon-recyclinginfluenced open-circuit voltage. The theoretical and experimental results show that for experimentally optimized perovskite solar cells with the power conversion efficiency of 19%, optical loss of 25%, nonradiative recombination loss of 35%, and ohmic loss of 35% are the three dominant loss factors for approaching the 31% efficiency limit of perovskite solar cells. It is also found that the optical loss climbs up to 40% for a thin-active-layer design. Moreover, a misconfigured transport layer introduces above 15% of energy loss. Finally, the perovskit...

A Review of Diverse Halide Perovskite Morphologies for Efficient Optoelectronic Applications

“…Taking PSCs for example, the first critical question comes to, how to reduce the optical loss and thus maximize the light harvesting efficiency within the PSCs? It has been reported that the optical loss in PSCs climbs up to 40% for the device based on the MAPbI 3 thin film with the thicknesses less than 240 nm, which means a large portion of incident light could not be efficiently absorbed and thus lowering the photocurrent density ( J sc ) . To approach the Shockley–Queisser efficiency limit of PSCs (≈31%), a more effective light management should be conducted.…”

“…In recent years, various low‐dimensional halide perovskites including 0D quantum dots (QDs), nanocrystals (NCs), 1D nanowires (NWs),8b,13 2D nanoplatelets (NPLs), and nanosheets (NSs) have been demonstrated as promising alternatives for obtaining fruitful progress in solar cells, LEDs, photodetectors, and lasers,8b owing to their unique quantum confinement effect, large surface‐to‐volume ratio, and anisotropic geometry . In addition, it is worth pointing out the emergence of textured perovskite, which show significantly distinct morphological features, namely, the porous matrix, rough surface, and preferential grains orientation.…”

Reducing Photovoltage Loss in Inverted Perovskite Solar Cells by Quantum Dots Alloying Modification at Cathode Contact

“…Particularly, PSCs with inverted planar structures have drawn great attention due to their low‐temperature solution‐process fabrication, which is compatible with roll‐to‐roll and flexible process and can be simply integrated into tandem solar cells . However, the device performance of inverted PSCs still lags behind that of regular structured PSCs, probably due to distinct open‐circuit voltage ( V OC ) loss induced by surface recombination . An effective surface modification is a still great challenge for pursuing higher‐performance inverted planar heterojunction PSCs.…”

“…The electrode contact and electron transport material are two of the most important considerations when developing perovskite (PVK) films, which are mainly attributed to complicated surface conditions with different types of defects formed on the exposed film surface during varied film forming and subsequent annealing processes . Accordingly, a variety of interfacial materials and various passivation techniques have been developed, and fullerenes, such as buckminsterfullerene (C60) or their derivatives, are the most popular electron transport materials for inverted structure PSCs .…”

Analysing the Prospects of Perovskite Solar Cells within the Purview of Recent Scientific Advancements

“…Recently, Wei et al reported that the maximum limit for conversion efficiency is 31%. They have also certified that the efficiency limit of perovskite can be improved with light trapping through h texturing [21].…”