Germanium compounds 22 Germanium 14 QC Physics 13 Tellurium compounds 9 Germaniums (Ge) 7 Silicon 7 Energy gap 6 Q Science (General) 5 Selenium compounds 5 Technology: general issues 5 Antimony compounds 4 Density functional theory 4 Gamma rays 4 History of engineering and technology 4 Measurements of 4 Photons 4 TK Electrical engineering. Electronics Nuclear engineering 4 Activity concentration 3 Calculations 3 Chemistry 3 Cosmology 3 Dosimetry 3 Electron scattering 3 Electronic structure 3 Energy 3 Germanium alloys 3 Lead compounds 3 Optical properties 3 Phase change materials 3 Phase change memory 3