Soon after the Nobel prize winning invention of the gas-filled multiwire proportional chamber (MWPC) by Charpak, and parallel to developments in microelectronics, a great deal of research was stimulated to develop the highest granularity gaseous detectors for achieving the highest spatial resolution. Solid-state detectors, on the other hand, can have three orders-of-magnitude higher density, and thus, they yield much smaller detector dimensions with substantially higher spatial and temporal resolution. Inspired by Charpak's MWPC and its micropattern variants, and parallel to developments in nanoelectronics, we propose a novel solid-state detector that utilizes amorphous selenium (a-Se) as the photoconductive film. A-Se is a room-temperature wide bandgap semiconductor that is readily produced uniformly over large area at substantially lower cost compared to crystalline solids (e.g., crystalline Si). It is the only amorphous material that produces avalanche gain at high fields and because only holes become hot carriers, avalanche selenium devices are linear-mode devices with a very low excess noise. Commercially, avalanche gain in a-Se enabled the development of the first optical camera with more sensitivity than human vision and, for example, capable of capturing astronomical phenomena such as auroras and solar eclipses. A-Se has ∼90% detection efficiency in the blue wavelength which makes it ideal to be coupled to blue-emitting scintillators for high-energy radiation detection. Finally, selenium films are physically evaporated and enable integration of the detector with the CMOS readout electronic on the same die. The major drawback of a-Se is its poor time-resolution and low carrier mobility due to shallow-traps, problems that must be circumvented for applications such as time-of-flight (TOF) imaging. Thus, we propose a nanopattern multi-well a-Se detector to enable the utilization of both avalanche multiplication gain and unipolar time-differential (UTD) cha