In this perspective, we present strategies that foster the expulsion of lead from perovskites to obtain a non-hazardous active material.

The use of divalent chalcogenides and monovalent halides as anions in a perovskite structure allows the introduction of 3 and 4 charged cations in the place of the 2 metal cations. Herein we report for the first time on the fabrication of solar cells exploiting methylammonium antimony sulfur diiodide (MASbSI) perovskite structures, as light harvesters. The MASbSI was prepared by annealing under mild temperature conditions, via a sequential reaction between antimony trisulfide (SbS), which is deposited by the chemical bath deposition (CBD) method, antimony triiodide (SbI), and methylammonium iodide (MAI) onto a mesoporous TiO electrode, and then annealed at 150 °C in an argon atmosphere. The solar cells fabricated using MASbSI exhibited power conversion efficiencies (PCE) of 3.08%, under the standard illumination conditions of 100 mW/cm.

Although antimony sulfoiodide (SbSI) exhibits very interesting properties including high photoconductivity, ferroelectricity, and piezoelectricity, it is not applied to solar cells. Meanwhile, SbSI is predominantly prepared as a powder using a high‐temperature, high‐pressure system. Herein, the fabrication of solar cells utilizing SbSI as light harvesters is reported for the first time to the best of knowledge. SbSI is prepared by solution processing, followed by annealing under mild temperature conditions by a reaction between antimony trisulfide, which is deposited by chemical bath deposition on a mesoporous TiO2 electrode and antimony triiodide, under air at a low temperature (90 °C) without any external pressure. The solar cells fabricated using SbSI exhibit a power conversion efficiency of 3.05% under standard illumination conditions of 100 mW cm−2.

Photodetectors with high photoelectronic gain generally require a high negative working voltage and a very low environment temperature. They also exhibit low response speed and narrow linear dynamic range (LDR). Here, an organic photodiode is demonstrated, which shows a large amount of photon to electron multiplication at room temperature with highest external quantum efficiency (EQE) from ultraviolet (UV) to near-infrared region of 5.02 × 10 % (29.55 A W ) under a very low positive voltage of 1.0 V, accompanied with a fast response speed and a high LDR from 10 to 10 mW cm . At a relatively high positive bias of 10 V, the EQE is up to 1.59 × 10 % (936.05 A W ). Inversely, no gain is found at negative bias. The gain behavior is exactly similar to a bipolar phototransistor, which is attributed to the photoinduced release of accumulated carriers. The devices at a low voltage exhibit a normalized detectivity (D*) over 10 Jones by actual measurements, which is about two or three order of magnitudes higher than that of the highest existing photodetectors. These pave a new way for realization of high sensitive detectors with fast response toward the single photon detection.