Photoconductors require high charge-carrier mobilities, sensitivity over a wide range of light levels, and good stability. Combining an organic semiconductor with environmentally benign inorganic nanoparticles is a rational means to develop photoconductors with such properties. However, an inhomogeneous distribution of nanoparticles in the active layer restricts both charge-carrier mobility and charge collection at an electrode. In this paper, ultrathin ZnO superstructured nanosheets are successfully synthesized by a solvothermal method. Time-dependent investigations show that the superstructured nanosheets assemble in solution during the growth process. Given that high-quality ZnO nanosheets are obtained, a hybrid photoconductor device with P3HT is fabricated and investigated. Sensitivity above 200% under simulated sunlight is obtained with good air stability. This study demonstrates a general approach to design photoconductors using hybrid nanomaterials.