Spectrolab, a Boeing subsidiary known for the manufacture of solar cells for satellites and spacecraft, has in recent years turned its attention to terrestrial solar cells to tap into the expanding alternative energy market. Now the California-based company has claimed a new solar cell efficiency record of 37.8 percent for a ground-based multi-junction cell without solar concentration.
While Spectrolab and others have achieved higher efficiencies with multi-junction solar cells, these were done using sunlight concentrated by lenses or mirrors onto the solar cells. The company says it was able to set a new record without concentration using a new class of high-efficiency multi-junction solar cell.
Unlike traditional silicon solar cells, multi-junction solar cells contain several different semiconductor materials. The interfaces between these different materials – which are known as p-n junctions – are tuned to different wavelengths of light to increase efficiency.
It hasn't been revealed which materials were used in this case, with the news release stating only that the 37.8 percent conversion was achieved "using a new class of high-efficiency multi-junction solar cell, created from two or more materials and leveraging Boeing technology that makes semiconductor materials more reliable."
The company doesn’t intend to rest on its laurels, with Spectrolab’s vice president for advanced technology, Nasser Karam saying the company’s technology has the potential for efficiencies of more than 45 percent, even under lower concentrations.
Source: Boeing
A high quality thermal collector barely achieves 70% eff so I doubt a hybrid PV plus thermal collector could match that overall eff. After your 38% of electricity, you'd be getting less than 32% of thermal at very best. Generally a joule of electrical energy is considered about 2x as useful as a joule of high grade heat. You'd be combining a relatively super efficient PV making valuable electricity with an inefficient thermal collector of low grade and dispersed thermal energy that would have limited thermal use. As for storing heat, you really need the heat to be high grade for storage to be economical.
What I want to see is a ranking of all existing solar panels on the market with a weighting of efficiency weighted against cost and tolerances to temperature extremes, to expected lifetime before output drops below 80% of factory. ie - solar panels suffer as temperatures increase, rapidly aging them, causing reduced output.