Potential of amorphous silicon for solar cells Appl. Phys. A 69, 155–167 (1999) / Digital Object Identifier (DOI) /s B. Rech, H. Wagner 蕭子軒 1

Outline 1. Fundamental properties of a-Si:H and its alloys 2. Solar cells based on a-Si:H 3. Light trapping and TCO development 2

Fundamental properties of a-Si:H and its alloys Disorder and the high content of bonded hydrogen high optical absorption coefficients and recombination losses SWE PECVD Band gap is around 1.7 eV.(C, Ge) P-i-n and n-i-p 3

a-Si:H p-i-n solar cell 4

FF & j sc V.S. i-layer 5

Stacked cells Improve the light stability Use different band gaps for the component cells 6

a-Si:H/a-Si:H/a-SiGe:H triple- junction solar cell 7

Cell structures 8

Roll-to-roll 9

TCO low electrical and optical losses, refractive index matching and light scattering back reflection (with metal) ITO 、 ZnO 、 SnO 2 Sputter etch 10

Superstrate technology 11

Superstrate technology 12

Substrate technology 13

Substrate technology 14

Examples of highly efficient a-Si- based solar cells 15

Summary Stabilized efficiencies exceeding 10% 。 13% for an a-Si:H/a-SiGe:H/a-SiGe:H triple-junction solar cell. amorphous silicon solar cell technology holds a great potential to become a major energy source in the next century. 16

Thanks for your attention ！ 17