High Mobility Semiconductors and Optoelectronic Devices

High mobility semiconductors constitute a class of materials in which charge carriers travel rapidly under an applied electric field, enabling devices that operate at high frequency, with low power consumption and minimal signal delay. Advances in crystal growth and nanoscale fabrication have extended this concept from traditional III–V compounds to two-dimensional and layered oxyselenides, offering a balance between sizeable bandgaps and ultrahigh carrier velocities. Parallel progress in optoelectronics has harnessed these semiconductors to create photodetectors, modulators and light-emitting devices with exceptional sensitivity, speed and spectral coverage. The global significance of this field spans high-speed data communication, environmental sensing, biomedical imaging and energy harvesting. Ongoing challenges include the integration of diverse materials into scalable heterostructures, the control of defects and interfaces at the atomic scale, and the optimisation of trade-offs between mobility, stability and optical absorption.

Research from Nature Portfolio

Recent studies have demonstrated that atomically thin oxyselenide crystals exhibit intrinsic ultrafast photodetection well into the infrared. Devices based on these materials achieve photoresponse times on the order of one picosecond and responsivities exceeding tens of amperes per watt, directly attributable to a moderate optical bandgap paired with exceptionally high electron mobility. Complementary work has focused on the native defect chemistry of layered oxyselenides, mapping the landscape of point defects that govern unintentional n-type behaviour. By elucidating the formation energies and electronic activity of vacancies and antisites, this research provides a route to defect-engineered films with improved carrier lifetimes and reproducible transistor performance.

High Mobility Semiconductors and Optoelectronic Devices publication trend

The graph below shows the total number of articles in high mobility semiconductors and optoelectronic devices across all publications each year (not limited to Nature Index journals).

Technical terms

Carrier mobility: A measure of how quickly electrons or holes move through a semiconductor when driven by an electric field.

Bandgap: The energy difference between the valence band and the conduction band that determines a semiconductor’s light absorption and emission properties.

Heterojunction: An interface between two dissimilar semiconductor materials that enables charge separation and tailored band alignment.

Responsivity: The ratio of photocurrent generated by a photodetector to the incident optical power, indicating sensitivity.

Field-effect transistor (FET): A device that modulates current flow in a semiconducting channel via an electric field applied to a gate electrode.

Two-dimensional materials: Crystalline solids consisting of single or few atomic layers, often exhibiting unique electronic and optical characteristics.

References

1. Ultrafast and highly sensitive infrared photodetectors based on two-dimensional oxyselenide crystals. Nature Communications (2018).
2. Native point defects of semiconducting layered Bi2O2Se. Scientific Reports (2018).
3. Materials properties and device applications of semiconducting bismuth oxyselenide. InfoMat (2024).
4. Preparation, properties, and electronic applications of 2D Bi2O2Se. Advanced Powder Materials (2023).
5. Recent Advances in the Growth Strategies, Multifunctional Properties, and Emerging Applications of Two‐Dimensional Non‐van der Waals Bismuth Oxychalcogenides and Prospective Heterostructures. Small Structures (2024).