The metal oxides/graphene composites are one of the most promising supercapacitors (SCs) electrode materials. However, rational synthesis of such electrode materials with controllable conductivity and electrochemical activity is the topical challenge for high‐performance SCs. Here, the Co₃O₄/graphene composite is taken as a typical example and develops a novel/universal one‐step laser irradiation method that overcomes all these challenges and obtains the oxygen‐vacancy abundant ultrafine Co₃O₄ nanoparticles/graphene (UCNG) composites with high SCs performance. First‐principles calculations show that the surface oxygen vacancies can facilitate the electrochemical charge transfer by creating midgap electronic states. The specific capacitance of the UCNG electrode reaches 978.1 F g⁻¹ (135.8 mA h g⁻¹) at the current densities of 1 A g⁻¹ and retains a high capacitance retention of 916.5 F g⁻¹ (127.3 mA h g⁻¹) even at current density up to 10 A g⁻¹, showing remarkable rate capability (more than 93.7% capacitance retention). Additionally, 99.3% of the initial capacitance is maintained after consecutive 20 000 cycles, demonstrating enhanced cycling stability. Moreover, this proposed laser‐assisted growth strategy is demonstrated to be universal for other metal oxide/graphene composites with tuned electrical conductivity and electrochemical activity.

Pulsed laser deposition (PLD) is a powerful growth technique for thin films, where in situ doping and post-thermal annealing are the most effective ways to tune the crystalline and physical properties of the deposited films. This paper demonstrates that the crystallinity, transparency, and electrical properties of NiO films are well controlled by PLD, which determines the photovoltaic performance of CH₃NH₃PbI_3−xCl_x-based perovskite solar cells with NiO films as the hole transport layers (HTLs). After post-annealing, the NiO films exhibit enhanced in-plane crystal orientation, high transmittance, and uniform surface morphology, and, accordingly, the power conversion efficiency (PCE) of the perovskite solar cell improves from 5.38% to 12.59%. Moreover, by doping the ablated target with lithium (Li), PLD can produce doped NiO:Li films with significantly enhanced electrical conductivity, which further improves the perovskite cell PCE from 12.59% to 15.51%. These results highlight the importance of optimizing the transporting layer properties toward high-performance inverted perovskite planar solar cells.

ZnO nanorods inorganic–organic heterostructured light-emitting diodes have been demonstrated on a cheap/disposable paper substrate and applied in multiplexed photoelectrochemical immunoassay.