Solar photovoltaic thermal energy systems1, or PVTs, generate both heat and electricity, but l now they2 havent been very good at the heat-generating part compared to a stand-alone3 solar thermal collector. Thats because they operate at low temperatures to cool crystalline silicon solar cells4, which5 1ets the silicon generate more 2 but isnt a very efficient way to gather heat.
Thats a problem of 3 Good solar hot-water systems can harvest much more energy than a solar-electric system at a substantially lower 4 . And its also a space problem：photovoltaic cells can take up all the space on the roof, leaving little room6 for thermal applications.
In a pair of studies, Joshua Pearce, an associate professor of materials science and engineering, has devised a 5 in the form of a better PVT made with a different kind of silicon. His research collaborators are Kunal Girotra from ThinSilicon in California and Michael Pathak and Stephen Harrison from Queens University, Canada.
Most solar panels7 are made with crystalline silicon, but you can also make solar cells out of amorphous silicon8, 6 known as thin-film silicon9. They dont create as much electricity, but they are lighter, flexible, and cheaper. And, because they 7 much less silicon, they have a greener footprint. Unfortunately, thin-film silicon solar cells are 8 to some bad-news physics in the form of the Staebler-Wronski effect10.
That means that their efficiency _ 9 when you expose them to light-pretty much11 the worst possible effect12 for a solar cell, Pearce explains, which is one of the 10 thin-film solar panels make up only a small fraction of the market.
However, Pearce and his team found a way to engineer around13 the Staebler-Wronski effect by incorporating thin-film silicon in a new 11 of PVT. You dont have to cool down thin-film silicon to make it work. In fact, Pearces group discovered that by heating it to solar-thermal operating temperatures14, near the boiling 12 of water, they could make thicker cells that largely.
13 the Staebler-Wronski effect. When they applied the thin-film silicon directly to a solar thermal energy 14 , they also found that by baking the cell once a day, they ____15____ the solar cells electrical efficiency by over 10 percent.
词汇：
photovoltaic .adj. 胛，光电的 silicon.n.硅
thermal.adj.热的，热量的 amorphous. adj.非品形的
crystalline.adj.晶体的 footprint .n.足迹
注释：
1. solar photovoltaic thermal energy systems：太阳能光伏热能系统
2. they：指代solar photovoltaic thermal energy systems。
3.stand-alone：单机的
4.crystalline silicon solar cells：晶体硅太阳能电池
5.which ：指前半句中的to cool crystalline silicon solar cells这件事
6.Room：空间
7.solar panels：太阳能电池板
8.amorphous silicon：非晶硅
9.thin-film silicon：薄膜硅
10.Staebler-Wronski Effect ：SWE效应。在光的照射下，非晶硅氢的导电性短时间内显著衰退，这种特性被称为SWE效应。
11. pretty much：几乎
12. the worst possible effect：最可能坏的效应
13. engineer around：精心地设计以克服或绕过
14. solar-thermal operating temperatures：太阳热能操作温度