Co-Ni Oxide Multiple Band Gap Alloy for Solar Efficiency
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Solution Overview
Problem
Conventional solar cells face limitations in efficiency due to the Shockley-Queisser limit, with high fabrication costs and low efficiencies in tandem and intermediate band semiconductor-based technologies, necessitating the development of alternative materials that can exceed theoretical efficiency limits.
Innovation Solution
The use of metal oxide compositions, specifically (Co,Ni)O alloys, which exhibit multiple band gaps in the visible light range, allowing for enhanced light absorption and potential efficiencies beyond current limits through their electronic structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional single band gap semiconductors are used in solar cells, then the device structure is simple and fabrication is easier, but light absorption efficiency is limited and power conversion efficiency cannot exceed the Shockley-Queisser limit
Solution Approach 1:
The patent changes the fundamental parameter of band gap structure from single to multiple band gaps. By engineering the electronic structure to include multiple band gaps, the material can absorb photons across a broader spectrum while maintaining a single junction structure, thereby exceeding the Shockley-Queisser limit without increasing device complexity
Solution Approach 2:
The patent employs composite material strategies by combining multiple semiconductor layers with different band gap energies in a single junction. This allows the material to function as both a light absorber and charge transporter with optimized band gap alignment, achieving high efficiency without the complexity of multi-junction devices
2Productivity
If multi-junction or tandem solar cells are used to exceed the Shockley-Queisser limit, then light absorption efficiency increases, but fabrication costs increase dramatically and scalability is limited
Solution Approach 1:
The patent merges the functions of multiple band gap absorption into a single junction structure. By integrating multiple absorption channels with different band gaps in one device, it achieves the light absorption efficiency of tandem cells while maintaining the fabrication simplicity and scalability of single junction devices
Solution Approach 2:
The patent creates a universal single junction structure that performs multiple functions: absorbing photons across different energy ranges through multiple band gaps, separating charges, and transporting carriers. This multi-functionality in a single structure eliminates the need for complex multi-junction fabrication
3Productivity
If intermediate band semiconductors are used to achieve efficiencies beyond the Shockley-Queisser limit, then theoretical efficiency increases, but material fabrication costs are prohibitive for commercial applications
Solution Approach 1:
The patent employs conventional semiconductor materials with well-established, cost-effective fabrication processes. By using materials that can be manufactured with existing industrial capabilities rather than exotic intermediate band materials, it achieves high efficiency at commercial fabrication costs
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The (Co,Ni)O alloys enable increased light absorption and multi-color emission, potentially achieving higher efficiencies and cost-effectiveness in solar energy conversion, making them suitable for photovoltaic and light-emitting diode applications.
Implementation Method 1
The (Co,Ni)O alloy includes a first band gap and a second band gap... allowing for enhanced light absorption
Implementation Method 2
The absorbed photons in turn excite electrons across the band gap, creating an electron-hole pair
Implementation Method 3
Typically, the built-in electric field in a pn junction separates this electron and hole, which will enter an external circuit
Data Source
AI summary
In one aspect, metal oxide compositions having electronic structure of multiple band gaps are described. In some embodiments, a metal oxide composition comprises a (Co,Ni)O alloy having electronic structure including multiple band gaps. The (Co,Ni)O alloy can include a first band gap and a second band gap, the first band gap separating valence and conduction bands of the electronic structure.