Hybrid CPbX 3 (C:C s, CH 3 NH 3 ;X :B r, I) perovskites possess excellent photovoltaic properties but are highly toxic, which hinders their practical application. Unfortunately,a ll Pb-free alternatives based on Sn and Ge are extremely unstable. Although stable and non-toxic C 2 ABX 6 double perovskites based on alternating corner-shared AX 6 and BX 6 octahedra (A = Ag, Cu;B = Bi, Sb) are possible, they have indirect and wide band gaps of over 2eV. However,i si tn ecessary to keep the corner-shared perovskite structure to retain good photovoltaic properties? Here, we demonstrate another family of photovoltaic halides based on edge-shared AX 6 and BX 6 octahedra with the general formula A a B b X x (x = a + 3 b)s uch as Ag 3 BiI 6 ,A g 2 BiI 5 ,A gBiI 4 , AgBi 2 I 7 .A sp erovskites were named after their prototype oxide CaTiO 3 discovered by Lev Perovski, we propose to name these new ABX halidesa sr udorffitesa fter Walter Rüdorff,w ho discoveredt heir prototype oxide NaVO 2 .W es tudied structural and optoelectronic properties of severalh ighly stable and promising Ag-Bi-I photovoltaic rudorffites that feature direct band gaps in the range of 1.79- Photovoltaic (PV) hybrid lead halide perovskites were first reported by Kojimae tal. [1] in 2006 with power conversion efficiency (PCE) of 2.2 %i nadye-sensitized solarc ell (DSSC) device configuration. However,t hese materials gained considerable attention only 6years later after two incremental improvements of their PCE to 3.8 %b yK ojimae tal. [2] and to 6.2 %b yI me tal. [3] Substitution of the liquid electrolyte with an efficient polymer hole-extraction layer by Lee et al. [4] in 2012 increased PCE to 10.9 %and was the turning point in perovskite photovoltaics that openedaway towardh ighly efficient and stable perovskite PV devices.S ince 2012 many researchers, mainly from the dye-sensitized and organic PV fields, joined the exciting research on perovskite solar cells. As ar esult, the PCE of the perovskite solarc ells showed as teep sigmoidal growth thatl ed to the contemporary efficiency of over 22 %. [5] Although this PCE is on par with other highly efficient thin-film PV technologies based on cadmium telluride (CdTe) and copper-indium-gallium selenide (CIGS), lead halide perovskites have the significant advantage of being solution processable, whicho fferss ubstantial cost reduction. Unfortunately,t he relianceo nh ighly toxic Pb hinders the commercial potentialo ft his technology. The toxicity of Pb is very high. The 50 %l ethal dose of lead [LD 50 (Pb)] is less than 5mgp er kg of body weight. In contrast to CdTe, which has excellent stability and negligible solubility in water with as olubility constant of K SP = 10 À34 ,P b-based halide perovskites can easily degrade and Pb can escape from ab roken PV module owing to the moderate solubility of PbI 2 (K SP = 4.4 10 À9 ). Despite various attempts to quantify the impact of potential pollution andi ntroduce life-cycle business modelst hat include integrity monitoring and recycling of perovskite PV modules, ...

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