文摘
Nanocarbon structures such as carbon nanotubes (CNTs) and graphene (G) have been combined with crystalline silicon wafers to fabricate nanocarbon鈥揝i solar cells. Here, we show that the contact between the nanocarbon and Si plays an important role in the solar cell performance. An asymmetrically configured CNT鈥揋 composite film was used to create either CNT鈥揝i dominating or G鈥揝i dominating junctions, resulting in obviously different solar cell behavior in pristine state. Typically, solar cells with direct G鈥揝i contacts (versus CNT鈥揝i) exhibit better characteristics due to improved junction quality and larger contact area. On the basis of the composite film, the obtained CNT鈥揋鈥揝i solar cells reach power conversion efficiencies of 14.88% under air mass 1.5, 88 mW/cm2 illumination through established techniques such as acid doping and colloidal antireflection. Engineering the nanocarbon鈥揝i contact is therefore a possible route for further improving the performance of this type of solar cells.