An electrically modulated single‐/dual‐color imaging photodetector with fast response speed is developed based on a small molecule (COi8DFIC)/perovskite (CH3NH3PbBr3) hybrid film. Owing to the type‐I ...heterojunction, the device can facilely transform dual‐color images to single‐color images by applying a small bias voltage. The photodetector exhibits two distinct cut‐off wavelengths at ≈544 nm (visible region) and ≈920 nm (near‐infrared region), respectively, without any power supply. Its two peak responsivities are 0.16 A W−1 at ≈525 nm and 0.041 A W−1 at ≈860 nm with a fast response speed (≈102 ns). Under 0.6 V bias, the photodetector can operate in a single‐color mode with a peak responsivity of 0.09 A W−1 at ≈475 nm, showing a fast response speed (≈102 ns). A physical model based on band energy theory is developed to illustrate the origin of the tunable single‐/dual‐color photodetection. This work will stimulate new approaches for developing solution‐processed multifunctional photodetectors for imaging photodetection in complex circumstances.
A tunable dual‐color imaging photodetector with a fast response speed (≈102 ns) is developed by constructing a type‐I p–n heterojunction of CH3NH3PbBr3/COi8DFIC. Dual‐color imaging can be switched to single‐color imaging by applying a small bias voltage.
Highlights
Wide-bandgap perovskite solar cells are reviewed in detail from the views of compositions, additives, charge transport layers, interfaces and preparation methods.
The key factors affecting ...open-circuit voltage and photostability are carefully discussed.
The future directions and challenges in developing wide-bandgap perovskite solar cells are highlighted.
Perovskite-based tandem solar cells have attracted increasing interest because of its great potential to surpass the Shockley–Queisser limit set for single-junction solar cells. In the tandem architectures, the wide-bandgap (WBG) perovskites act as the front absorber to offer higher open-circuit voltage (
V
OC
) for reduced thermalization losses. Taking advantage of tunable bandgap of the perovskite materials, the WBG perovskites can be easily obtained by substituting halide iodine with bromine, and substituting organic ions FA and MA with Cs. To date, the most concerned issues for the WBG perovskite solar cells (PSCs) are huge
V
OC
deficit and severe photo-induced phase separation. Reducing
V
OC
loss and improving photostability of the WBG PSCs are crucial for further efficiency breakthrough. Recently, scientists have made great efforts to overcome these key issues with tremendous progresses. In this review, we first summarize the recent progress of WBG perovskites from the aspects of compositions, additives, charge transport layers, interfaces and preparation methods. The key factors affecting efficiency and stability are then carefully discussed, which would provide decent guidance to develop highly efficient and stable WBG PSCs for tandem application.
The perovskite solar cell (PSC) has been recognized as a promising candidate for the next generation of photovoltaics due to its excellent power conversion efficiency (PCE), potential low cost and ...straightforward solution preparation processes. With efforts around the world, the PCE of PSCs has reached 25.7%. As the perovskite film is the most important part of a PSC, its quality dramatically affects the efficiency and stability of the PSC. Numerous works have focused on controlling crystallization to realize oriented growth of perovskite films. Particularly, considering the photoelectric anisotropy of perovskite materials, it is very meaningful to investigate the relationship between preferred crystal orientation and device efficiency and stability. This review highlights various approaches for realizing preferred crystal orientation of polycrystalline perovskite films, including optimizing the perovskite precursor solution and film annealing process, additive engineering, and interface engineering. Furthermore, the key factors affecting oriented crystal growth are carefully discussed, which provides effective guidance to obtain highly‐oriented perovskite films for highly efficient and stable PSCs.
Modulating the growth of perovskite crystals along the preferred orientation is crucial for highly efficient and stable perovskite solar cells. This review summarizes various effective strategies for oriented crystal growth and corresponding mechanisms for improving device performance. Further investigation of facet‐dependent efficiency and stability variation would further promote the development of perovskite‐based photovoltaics.
Abstract Background Non-small cell lung cancer (NSCLC) is the major pathological type of lung cancer and accounts for the majority of lung cancer-related deaths worldwide. We investigated the ...molecular mechanism of prominin 2 (PROM2) involved in cisplatin resistance in NSCLC. Patients and methods The GEO database was analyzed to obtain differential genes to target PROM2. Immunohistochemistry and western blotting were used to detect protein expression levels. To examine the role of PROM2 in NSCLC, we overexpressed or knocked down PROM2 by transfection of plasmid or small interfering RNA. In functional experiments, CCK8 was used to detect cell viability. Cell migration and invasion and apoptosis were detected by transwell assay and flow cytometry, respectively. Mechanistically, the regulation of PROM2 by CTCF was detected by ChIP-PCR. In vivo experiments confirmed the role of PROM2 in NSCLC. Results GEO data analysis revealed that PROM2 was up-regulated in NSCLC, but its role in NSCLC remains unclear. Our clinical samples confirmed that the expression of PROM2 was markedly increased in NSCLC tissue. Functionally, Overexpression of PROM2 promotes cell proliferation, migration and invasion, and cisplatin resistance. CTCF up-regulates PROM2 expression by binding to its promoter region. In vivo experiments confirmed that PROM2 knockdown could inhibit tumor growth and increase the sensitivity of tumor cells to cisplatin. Conclusions PROM2 up-regulation in NSCLC can attenuate the sensitivity of NSCLC cells to cisplatin and promote the proliferation, migration and invasion of tumor cells. PROM2 may provide a new target for the treatment of NSCLC.
Wide‐bandgap (≥1.68 eV) inverted perovskite solar cells (PSCs) have been recognized as promising top component cells on the commercial crystalline silicon cell to surpass its Shockley–Queisser ...efficiency limit. However, the power conversion efficiency (PCE) is dramatically limited by the huge open‐circuit voltage (VOC) loss. Herein, we propose a proton‐transfer‐induced in situ defect passivation strategy to reduce the nonradiative recombination to minimize the VOC loss. Specifically, a liquid‐form neutral amine, 3,4,5‐trifluorobenzylamine (TFBA) was added into ethyl acetate (EA) as anti‐solvent for the film preparation, which induces proton‐transfer from the formamidinium (FA) and methylammonium (MA) in the perovskite precursors to the TFBA. The protonated TFBA exhibits a gradient distribution near the surface of the perovskite film, achieving in situ defect passivation. As a result, TFBA‐based 1.68 eV‐bandgap inverted PSCs afforded a PCE of 20.39%, one of the highest for cells with this bandgap. Meanwhile, due to the strong interaction between TFBA and the perovskite film, the mixed‐halide perovskites demonstrate much better photostability. Our findings offer an effective strategy to passivate defects in PSCs.
In situ defect passivation is achieved via introducing 3,4,5‐trifluorobenzylamine (TFBA) into ethyl acetate (EA) as anti‐solvent during the perovskite film preparation. The 1.68 eV bandgap inverted perovskite solar cell with TFBA incorporation delivers an excellent power conversion efficiency of 20.39%, one of the highest for cells with this bandgap.
Developing perovskite-based tandem solar cells (TSCs) is a promising technique to surpass the Shockley-Queisser limit set for single-junction solar cells. Encouragingly, all the perovskite-based ...TSCs, including perovskite/silicon, perovskite/perovskite, perovskite/copper indium gallium selenide and perovskite/organic tandems have demonstrated higher efficiency than the corresponding single-junction solar cells, showing great potential for further breakthroughs. In tandem devices, charge transport materials (CTMs) are vital components of perovskite sub-cells that directly determine the charge transportation and energy loss. Generally, high conductivity and transmittance, favorable energy-level alignment and chemical stability are crucial for CTMs for tandem applications. To date, various CTMs including conductive metallic oxides, organic molecules, polymers, fullerenes, and self-assembled materials have been extensively employed in highly efficient TSCs. In this review, we first summarize the recent progress of CTMs for different types of monolithic perovskite-based TSCs, in which the electrical and optical properties of CTMs and their influence on device performance are carefully discussed. Then we put forward the challenges and outlook for the further development of CTMs for tandem applications. This comprehensive review will provide effective guidance for device design for different perovskite-based TSCs.
Metal halide perovskite solar cell (PSC) has successfully distinguished itself in optoelectronic field by virtue of the sharp rise in power conversion efficiency over the past decade. The remarkable ...efficiency breakthrough at such a fast speed can be mainly attributed to the comprehensive study on film deposition techniques, especially the effective management of surface and interfacial defects in recent works. Herein, we summarized the current trends in performance enhancement for PSCs, with a focus on the generally applicable strategies in high-performance works, involving deposition methods, compositional engineering, additive engineering, crystallization manipulation, charge transport material selection, interfacial passivation, optical coupling effect and constructing tandem solar cells. Promising directions and perspectives are also provided.
Judicious tailoring of the interface between the SnO2 electron‐transport layer and the perovskite buried surface plays a pivotal role in obtaining highly efficient and stable perovskite solar cells ...(PSCs). Herein, a DL‐carnitine hydrochloride (DL) is incorporated into the perovskite/SnO2 interface to suppress the defect‐states density. A DL‐dimer is obtained at the interface by an intermolecular esterification reaction. For the SnO2 film, the Cl− in the DL‐dimer can passivate oxygen vacancies (VO) through electrostatic coupling, while the N in the DL‐dimer can coordinate with the Sn4+ to passivate Sn‐related defects. For the perovskite film, the DL‐dimer can passivate FA+ defects via hydrogen bonding and Pb‐related defects more efficiently than the DL monomer. Upon DL‐dimer modification, the interfacial defects are effectively passivated and the quality of the resultant perovskite film is improved. As a result, the DL‐treated device achieves a gratifying open‐circuit voltage (VOC) of 1.20 V and a champion power conversion efficiency (PCE) of 25.24%, which is a record value among all the reported FACsPbI3 PSCs to date. In addition, the unencapsulated devices exhibit a charming stability, sustaining 99.20% and 90.00% of their initial PCEs after aging in air for 1200 h and continuously operating at the maximum power point tracking for 500 h, respectively.
DL‐Carnitine hydrochloride (DL) is incorporated into the perovskite/SnO2 interface for FACsPbI3 perovskite solar cells (PSCs). Oxygen vacancies and Sn‐related defects are concurrently suppressed by the DL, while the DL‐dimer yielded by the intermolecular esterification passivates Pb‐related defects more efficiently than DL. Consequently, a DL‐treated device achieves a record efficiency of 25.24% among all the reported FACsPbI3 PSCs to date.
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