A neutron detector, and method for fabricating same, having an active layer comprised of organic and inorganic materials such as polymers and/or small molecules. These materials function as a semiconductor host matrix that transports carriers excited by neutron absorption. The active layer is comprised of host semiconductor materials, composites of the host semiconductor materials with other polymers molecules, and particles, or multi-layer structures of the host semiconductor materials with other materials. The host semiconductor materials include in their molecular structure neutron capturing atoms such as 10B, 6Li, 157Gd, 235U, 239Pu, 51V, and 103Rh, or alternatively are blended with molecules or particles that contain the above atoms in addition to electron accepting molecules or particles. Using these materials allows for the simplified fabrication of inexpensive, large area, relatively lightweight, and flexible neutron detectors via film casting from solution, thermal evaporation, inkjet printing, and film laminate, or film extrusion.