Dissolution Study of Biodegradable Magnesium Silicide Thin Films for Transient Electronic Applications

Area of Science:

• Materials Science
• Sustainable Technology
• Semiconductor Physics

Background:

• Transient electronic systems require biodegradable materials for sustainable disposal and safe biomedical applications.
• Biodegradable semiconductors are crucial for logic and sensing in transient devices.

Purpose of the Study:

• To investigate magnesium silicide (Mg2Si) thin films as a narrow-bandgap, biodegradable semiconductor for transient electronics.
• To evaluate the material's properties, biodegradability, biocompatibility, and device performance.

Main Methods:

• Mg2Si thin films were fabricated using RF magnetron sputtering and thermal annealing.
• Dissolution behavior was studied under various pH and ionic conditions, including phosphate-buffered saline and composting.
• In vitro cytotoxicity assays were performed.
• Electrical, optical, and thermal properties were characterized.
• Device-level integration into thermoelectric harvesters and photosensors was conducted.

Main Results:

• Mg2Si thin films demonstrated biodegradability in physiological and environmental conditions and were biocompatible.
• The material exhibits an indirect bandgap of ~0.84 eV, high carrier concentration (>10^18 cm^-3), and broadband optical absorbance.
• Thermoelectric harvesters achieved Seebeck coefficients of ~130 µV/K and output power >0.338 µW/cm^2/K^2.
• Photosensors showed photoresponse up to 1300 nm, indicating near-infrared sensitivity.

Conclusions:

• Mg2Si is a viable semiconductor material for transient electronics, offering a new option beyond wide-bandgap semiconductors.
• Its tunable properties and biodegradability support applications in sustainable and biomedical transient devices.