Germanium - Material Information

Germanium is a lustrous, brittle metalloid that serves as a cornerstone of semiconductor technology. Discovered by C.A. Winkler in 1886, germanium’s exceptional semiconducting behavior bridges the gap between metallic and nonmetallic materials. Its precise control of charge carrier concentration, moderate bandgap, and high refractive index make it indispensable for infrared optics, fiber communications, and thermoelectric devices.

Material Overview

Germanium crystallizes in a diamond-cubic lattice structure with an energy bandgap of approximately 0.66 eV at 300 K. It exhibits an electrical resistivity of around 47 Ω·cm for intrinsic Ge and a thermal conductivity of approximately 58 W·m⁻¹·K⁻¹. Recent investigations by Voronena and Troshina (2023) revealed that doped n-type and p-type germanium exhibit energy bandgaps between 0.50–0.72 eV, depending on impurity levels, confirming its tunability for electronic and photonic applications. Furthermore, Chae et al. (2020) reported that rutile germanium dioxide (r-GeO₂), a derivative form, demonstrates an impressive thermal conductivity up to 58 W·m⁻¹·K⁻¹ at 300 K, suggesting potential for high-power electronics. Alloying germanium with tin (Ge_1−xSn_x) has also been shown by Ayinde and Myronov (2023) to drastically reduce thermal conductivity — down to 2.5 W·m⁻¹·K⁻¹ — while maintaining semiconductor compatibility, opening avenues for thermoelectric applications.

Applications and Advantages

Germanium’s intermediate electronic bandgap, high carrier mobility (~3900 cm²/V·s for electrons), and strong optical transparency in the infrared range (2–14 ?m) enable its use in photodetectors, transistors, and infrared lenses. In thermoelectric research, silicon–germanium (Si?.??Ge?.??) alloys have shown exceptional high-temperature stability and power generation efficiency up to 1200 °C (Inglizian et al., 2016). In advanced materials science, germanium-doped silicene films demonstrate reduced phonon thermal transport, as Guo et al. (2016) found, improving thermoelectric conversion efficiency. Together, these findings establish germanium and its alloys as pivotal materials for semiconductor, energy, and photonics technologies.

Goodfellow Availability

Goodfellow supplies high-purity Germanium (Ge) in multiple physical forms—including foils, wires, rods, and powders—for use in semiconductor fabrication, optical systems, and thermoelectric research. Each product undergoes stringent purity control to ensure consistent electronic and structural properties. Custom geometries and tailored purity levels are available upon request for specialized applications in electronics and energy systems.

Explore Germanium (Ge) and other advanced materials in Goodfellow’s online catalogue: Goodfellow product finder.

References

• Chae, S., Mengle, K., Lu, R., Olvera, A., Sanders, N., Lee, J. Y., Poudeu, P. F. P., Heron, J. T., & Kioupakis, E. (2020). Thermal conductivity of rutile germanium dioxide. Applied Physics Letters, 117(10), 102102.
• Ayinde, S., & Myronov, M. (2023). Revealing low thermal conductivity of germanium tin semiconductor at room temperature. Advanced Materials Interfaces, 10(21), 2300711.
• Inglizian, P. N., Mikheyev, V. K., Novinkov, V. V., & Shchedrov, E. R. (2016). On the thermoelectric properties and band gap of silicon–germanium alloys in the high-temperature region. Semiconductors, 50(4), 503–508.
• Guo, Y., Zhou, S., Bai, Y., & Zhao, J. (2016). Tunable thermal conductivity of silicene by germanium doping. Journal of Superconductivity and Novel Magnetism, 29(3), 687–693.
• Voronena, N., & Troshina, G. V. (2023). Investigation of the electrical properties and carrier concentration in n- and p-doped germanium. Technobius Physics, 2(4), 22–29.