Lead‐Free Perovskite‐Inspired Absorbers for Indoor Photovoltaics

Abstract

sources at 1000 lux had an irradiance of 340 and 320 µW cm −2 , respectively. The accuracy of the light meter and power meter is the primary determinant of the uncertainty in the measured PCE values, which amounts to approximately ±6-7%, as can be determined from a straightforward uncertainty analysis based on the device testing conditions and the specifications of the power and light meters. Consequently, the PCE values are reported herein with 1 decimal place.

Assessing the Impact of Defects on Lead‐Free Perovskite‐Inspired Photovoltaics via Photoinduced Current Transient Spectroscopy

“…For the sake of comparison, we additionally carried out the same analysis on MAPbI 3 , using literature values of the relevant quantities (see also Table S6-S8, Supporting Information). [25,32,87,88] As a general trend, the one-center EQE associated with all defect levels monotonically increases with the carrier mobility and eventually saturates (Figure 5), consistent with the physical picture that a high mobility allows a larger fraction of photocarriers to escape recombination. Moreover, the one-center ΔV oc,nr monotonically decreases with carrier density (Figure 5), consistent with the concurrent reduction in the weight of the nonradiative recombination.…”

“…[19][20][21] In addition to solar photovoltaics, PIMs have considerable potential for indoor photovoltaics (IPVs), building-integrated photovoltaics, tandem photovoltaics, photocathodes for water splitting, photodetectors, light-emitting devices, and radiation detectors. [21][22][23][24][25][26][27][28][29][30][31] In view of the key role that defect tolerance has played in determining the success of lead-halide perovskites, identifying how defect tolerance arises and how it can be designed into a material has been a key driving force for PIM development. [7,8,23,[32][33][34] While the concept of defect tolerance has not been rigorously and quantitatively defined, with different interpretations being proposed, [8,23,32,35,36] an absorber is generally regarded as defect tolerant if its compositional and structural defects result in electronic states (so-called defect levels) that are either "shallow," or with small capture cross-sections, or that fall within the energy bands (Figure 1a,b).…”

“…PCE is up to 5.6% for silver bismuth sulfoiodides under AM 1.5G illumination, [40] while the IPV efficiencies are up to ≈5% for Cs 3 Sb 2 Cl x I 9−x and BiOI (i.e., already within the same range of IPV industry-standard hydrogenated amorphous silicon). [25] Given the essential role that defects play in determining the photovoltaic performance and potential of PIMs, a quantitative experimental characterization of their defect properties would be highly beneficial to the field as a whole because: it would contribute to the identification of the most promising PIMs without extensive device optimization; it would allow the rational identification of the relationship between defect tolerance and structure/composition; it would catalyze the development of defect-healing strategies; and it would provide a much needed experimental support to computational studies, thereby potentially aiding the discovery of new defect-tolerant absorbers. Specifically, such a characterization should allow the determination of the so-called defect-level parameters (or defect parameters, in short)-i.e., volumetric concentration, energy depth, and capture cross-section-for each of the defect levels present.…”

Wide-Bandgap Halide Perovskites for Indoor Photovoltaics

“…It should be noted that, among the various perovskite-based IPVs reported so far, this bandgap-tuned composition of 1.8 eV has resulted in the highest Voc (>1 V) under 1,000 lux white LED indoor illumination. Pb-free perovskites are also gaining attention in indoor PV application and a very recent report showed a PCE of 4.5% under white LED illumination ( Peng et al, 2020 ). In Figure 2D , the power conversion efficiency of halide perovskite indoor photovoltaics as a function of their composition is provided.…”

The Impact of Cesium and Antimony Alloying on the Photovoltaic Properties of Silver Bismuth Iodide Compounds

“…They are used in cases, such as indoor photovoltaics (IPV), light-emitting diodes (LEDs), photodetectors, and high-performance X-ray detectors. [11][12][13][14] It seems that the Bi-based absorber materials are the best replacement for Pb-based ones because of their ideal optoelectronic properties. Trivalent bismuth (Bi 3þ ) has a lone pair of 6s 2 electrons (isoelectronic with Pb 2þ ), and because of high born effective charges, these lone pair cations could have high dielectric constants.…”