High Electron Mobility of Amorphous Red Phosphorus Thin Films

Area of Science:

• Materials Science
• Condensed Matter Physics
• Semiconductor Research

Background:

• Black phosphorus (BP) is highly valued for electronic and optoelectronic uses due to its excellent electron mobility and high current switching ratios.
• However, BP's high cost and low synthetic yield limit its widespread application.
• Red phosphorus (RP), an alternative allotrope, is affordable and easily processed, but traditionally considered an insulator.

Purpose of the Study:

• To investigate the electronic properties of amorphous red phosphorus (a-RP) films.
• To explore methods for improving the stability of a-RP films for potential electronic applications.
• To compare the performance of a-RP with established materials like black phosphorus.

Main Methods:

• Fabrication of a-RP films using thermal evaporation and drop-casting techniques on Si/SiO2 substrates.
• Characterization of a-RP films using field-effect transistor (FET) measurements.
• Investigation of a-RP film oxidation and stabilization through metal oxide doping.

Main Results:

• Amorphous red phosphorus (a-RP) films demonstrate semiconducting behavior.
• High electron mobility (387 cm²/V·s) and a current switching ratio (≈10³) were achieved, comparable to black phosphorus.
• Metal oxide doping significantly improved film stability, maintaining performance over one thousand I-V cycles without degradation.

Conclusions:

• Amorphous red phosphorus is a promising semiconducting material for electronic and optoelectronic applications.
• The facile synthesis and improved stability of doped a-RP offer a cost-effective alternative to black phosphorus.
• Further research into doped a-RP could lead to new advancements in semiconductor technology.