Wide Bandgap Photodectors

Wide band gap semiconductors offer the potential for low noise photodetection with high quantum efficiency. By varying the composition of ternary compounds, the band gap can be tuned and quantum efficiency can be optimized to efficiently detect light from a scintillator with a given emission spectrum. High light output scintillators coupled with wide band gap semiconductor photodetectors offer the promise of high detection efficiency and energy resolution superior to PMT-based detectors. Figure 1 shows photographs of thallium bromoiodide (TlBr1-xIx), a wide band gap ternary compound semiconductor, with various compositions grown by the traveling molten zone method at RMD. The dependence of band gap on composition is evident from the color change.