We report a careful and systematic study of thermal and photochemical degradation of a series of complex haloplumbates APbX (X = I, Br) with hybrid organic (A = CHNH) and inorganic (A = Cs) cations under anoxic conditions (i.e., without exposure to oxygen and moisture by testing in an inert glovebox environment). We show that the most common hybrid materials (e.g., MAPbI) are intrinsically unstable with respect to the heat- and light-induced stress and, therefore, can hardly sustain the real solar cell operation conditions. On the contrary, the cesium-based all-inorganic complex lead halides revealed far superior stability and, therefore, provide an impetus for creation of highly efficient and stable perovskite solar cells that can potentially achieve pragmatic operational benchmarks.

[3]-Radialene-based dopant CN6-CP studied herein, with its reduction potential of +0.8 versus Fc/Fc+ and the lowest unoccupied molecular orbital level of -5.87 eV, is the strongest molecular p-dopant reported in the open literature, so far. The efficient p-doping of the donor-acceptor dithienyl-diketopyrrolopyrrole-based copolymer having the highest unoccupied molecular orbital level of -5.49 eV is achieved. The doped films exhibit electrical conductivities up to 70 S cm(-1) .

achieve the highest performance so far in combination with the commonly used methanofullerene derivatives like phenyl-C 61 -butyric acid methyl ester ([60]PCBM) or [6,6]-phenyl-C 71 -butyric acid methyl ester ([70]PCBM). [11] Functional fullerenes, on the one hand, can preserve the properties of pristine fullerenes, such as superior electron-transporting ability and high electron affinity. On the other hand, by properly attaching suitable addends, one can manipulate a wide variety of chemical, physical, or thermo dynamic properties, such as better solubility in organic solvents, higher lowest unoccupied molecular orbital (LUMO) level, and improved compatibility with organic donors. [12] These advantages endow functional fullerenes with extraordinary capability, acting as unique electron-accepting components in OPV devices. [2,13] Although PCBM is the most prominent acceptor in OPV devices, [5,14] the energy levels of PCBM should be further optimized in order to achieve high open circuit voltage (V OC ) in combination with the state-of-theart organic donors. [15] Fullerene derivatives with more suitable electronic levels are expected to reduce the bandgap to V OC loss and approach the theoretical efficiency limit. [13,16] PCBM bisadduct [17] and indene-C 60 bisadduct [18] made their glory debut for being well compatible with poly(3-hexylthiophene-2,5-diyl) (P3HT) and for achieving promising high V OC and PCE compared to the PCBM-based counterparts. However, resulting from constitutional isomer impurities and inefficient charge generation, fullerene bisadducts failed to produce similarly satisfying performance with the latest outstanding organic donors. [19] Another effective way of increasing the LUMO level of fullerene derivatives is to add an electron-donating group to the fullerene cage. [20] A series of newly developed functional fullerenes have shown higher photovoltaic performance than PCBM resulting from their high-lying LUMO levels. Itoh and co-workers carried out a systematic study on a series of fulleropyrrolidine derivatives, some of which possess higher V OC and efficiency than PCBM when blended with P3HT. [21] Troshin and co-workers reported that solar cells based on the novel pyrrolidinofullerene acceptors exhibited impressively high V OC and promising efficiency in combination with Poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) and P3HT compared to the PCBM-based references. [22] As the PCE of OPV devices was improved to over 11%, currently, more research efforts are required to address the long-term stability issue. Many factors may cause degradation Extensive research efforts around the world have been devoted to organic photovoltaics (OPV) over the last decade due to their unique advantages for commercial application, such as low cost, light weight, flexibility, and easy manufacture on large-scale. [1][2][3] By introducing the bulk heterojunction (BHJ) [4,5] structure into OPV devices, tremendous progress has been achieved to boost the powe...

Here we report a systematic study of the Pb substitution in the hybrid iodoplumbate MAPbI with a series of elements affecting optoelectronic, structural, and morphological properties of the system. It has been shown that even partial replacement of lead with Cd, Zn, Fe, Ni, Co, In, Bi, Sn, and Ti results in a significant deterioration of the photovoltaic characteristics. On the contrary, Hg-containing hybrid MAPbHgI salts demonstrated a considerably improved solar cell performance at optimal mercury loading. This result opens up additional dimension in the compositional engineering of the complex lead halides for designing novel photoactive materials with advanced optoelectronic and photovoltaic properties.

F substituents & bulky alkyl side-chains for polymer:fullerene face-on orientation and high PV performances.