Towards improved photovoltaic conversion using dilute magnetic semiconductors (abstract only)

Area of Science:

• Materials Science
• Solid State Physics
• Renewable Energy Technologies

Background:

• Current p/n junction photovoltaic devices are limited to 31% efficiency (Shockley-Queisser limit), with multi-junction devices reaching ~41%.
• Innovative schemes, like intermediate level semiconductor (ILSC) concepts, offer theoretical efficiencies over 85% but suffer from high non-radiative recombination.
• Overcoming the Shockley-Queisser limit is crucial for advancing solar energy conversion.

Purpose of the Study:

• To propose a ferromagnetic impurity scheme to reduce non-radiative recombination in ILSC solar cells.
• To maintain the high theoretical maximum efficiency of ILSC devices (~46%).
• To identify suitable semiconductor materials and impurities for this application.

Main Methods:

• Utilized density functional theory (DFT) calculations to analyze electronic and energetic properties.
• Screened a wide range of semiconductors and transition metal impurities.
• Defined specific design criteria for effective ferromagnetic impurity schemes.

Main Results:

• Identified a few promising compounds that meet the design criteria from several hundred studied.
• Demonstrated that incorporating Manganese (Mn) into Aluminum Phosphide (AlP) can induce beneficial band structures.
• Achieved potential conversion efficiencies close to the theoretical maximum with an estimated Curie temperature above 100 K.

Conclusions:

• The proposed ferromagnetic impurity scheme shows promise for significantly enhancing solar cell efficiency.
• Wide gap AlP with Mn impurities is a leading candidate material for next-generation solar cells.
• This approach could pave the way for solar energy conversion efficiencies approaching theoretical limits.