We report an innovative, low-cost, solid-state neutron detector based on the technology of thin-film CdTe solar cells activated with layers of isotopically enriched metallic Li-6. The technology leverages recent advances in thin-film solar-module manufacturing and lithium sources for electrochromic window fabrication. Our detector inherently has very high rejection of gamma events and strong directional sensitivity; it is readily scalable in size from personal radiation monitors to radiation portal monitors. The thermal neutron response of a double detector stack is competitive with and/or exceeds responses reported for other portable detectors such as a small He-3 tube, a CLYC-based scintillator, or a microstructured semiconductor detector.