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Summary Silver (Ag)‐doped PbS (PbS:Ag) thin films of 616 to 745 nm in thickness were prepared on glass substrates via cost‐effective nebulizer spray method by adding different Ag levels from 2% to 8% at 200°C. For solar cell applications, the effect of Ag doping concentration on structural, morphological, optical, photoluminescence, and electrical chattels of PbS thin film has been studied. X‐ray diffraction pattern confirmed the polycrystalline behavior of the prepared PbS:Ag films with cubic crystalline nature. The crystalline size and texture coefficient were increased by increasing Ag doping concentration. From the morphological studies by scanning electron microscope (SEM) and atomic force microscope (AFM), the grain size of the films and surface roughness values were increased for the increase in Ag doping concentration. EDS spectra confirmed the existence of Ag, Pb, and S elements in the select 6% Ag‐doped PbS film. Peaks related to silver oxide started to emerge at 6% of Ag doping level. The optical direct band gap value was reduced from 1.51 to 1.17 eV for Ag doping from 2% to 6% and thereby slightly increased as 1.79 eV for 8% Ag doping level. For all PbS:Ag films, the photoluminescence spectrum emitted a strong near band edge (NBE) emission at approximately 580 nm, meaning better optical quality. Hall effect measurements evidenced that Ag doping provides enhancement on the characteristics of mobility, carrier concentration, and resistivity with p‐type conducting nature. The observed high carrier concentration and low resistivity values were 4.32 × 1014 cm−3 and 80 Ωcm, for 6% Ag‐doped PbS film. The FTO/CdS/PbS:Ag heterostructure solar cell was formed from 6% Ag‐doped film.

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Organic bistable devices (OBDs) using graphene oxide (GO) flakes sandwiched polymethylmethacrylate (PMMA) films were fabricated. These devices exhibited two accessible conducting states, that is, a low-conductivity (OFF) state and a high-conductivity (ON) state. The devices can be switched to ON state under a negative electrical sweep; it can also be reset to the initial OFF state by a reverse (positive) electrical sweep. Detailed I-V measurements have shown that in ITO/PMMA/GO/PMMA/Al sandwiches the resistive switching originates from the formation and rupture of conducting filaments. The ON/OFF ratio of the OBDs was approximately 5 x 10(3), reproducibility of more than 10(5) cycles, and retention time of 10(4) s. These properties show that the device is promising for high-density, low-cost memory application.

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