We report on the growth of geometric feature tuned semiconductor nanotubes on a transparent substrate through the application of an anodic aluminum oxide membrane-assisted method. Three-dimensional nanotube solar cell...We report on the growth of geometric feature tuned semiconductor nanotubes on a transparent substrate through the application of an anodic aluminum oxide membrane-assisted method. Three-dimensional nanotube solar cells are developed in which semiconductor absorbers are not only used to fill the inner core of the nanotubes, but also to replace the membrane and to fill the intertube space between the nanotubes. The nanotube solar cells generate and separate carriers in three dimensions, namely, inside the cores of the nanotubes, in the intertube space between the nanotubes along the radial direction, and above the nanotubes along the axial direction. In preliminary experiments conducted to demonstrate the potential of this approach, nanotube CdS-CdTe solar cells were fabricated. CdS nanotubes with an inner diameter, wall thickness and intertube spacing of 35, 20, and 35 nm, respectively, were grown; the porosity and CdS nanotube density were 36.5% and 2.26 × 10^10 nanotubes/cm^2, respectively. These features of CdS nanotubes enable more efficient carrier collection because of the reduced recombination, especially in those cases in which the minority carrier lifetime is short, thus resulting in a diffusion length of less than 100 nm. Nanotube CdS-CdTe solar cells exhibit a wide and strong spectral response and quantum efficiency, indicating enhanced light absorption and carrier generation and collection. Without the benefit of an antireflection coating, the cells exhibited a wide and strong spectral response of quantum efficiency, and a short current density of 25.5 mA/cm^2, an open circuit voltage of 750 mV, and a power conversion efficiency of 10.7% under 1-sun illumination. The materials and electro-optical characterizations indicated well-defined junction and interface behavior in these 3D nanotube solar cell configurations.展开更多
基金Acknowle dgements This work was supported in part by grants from the National Science Foundation （Nos. NSF-NIRT-ECS- 0609064 and NSF-EPCOR EPS-0447479） and by grants from the Kentucky Science and Engineering Foundation （Nos. KSEF-148-502-02-27 and KSEF-148-502-03-68）. The authors would like to thank PV measurements, Inc for quantum efficiency measurement.
文摘We report on the growth of geometric feature tuned semiconductor nanotubes on a transparent substrate through the application of an anodic aluminum oxide membrane-assisted method. Three-dimensional nanotube solar cells are developed in which semiconductor absorbers are not only used to fill the inner core of the nanotubes, but also to replace the membrane and to fill the intertube space between the nanotubes. The nanotube solar cells generate and separate carriers in three dimensions, namely, inside the cores of the nanotubes, in the intertube space between the nanotubes along the radial direction, and above the nanotubes along the axial direction. In preliminary experiments conducted to demonstrate the potential of this approach, nanotube CdS-CdTe solar cells were fabricated. CdS nanotubes with an inner diameter, wall thickness and intertube spacing of 35, 20, and 35 nm, respectively, were grown; the porosity and CdS nanotube density were 36.5% and 2.26 × 10^10 nanotubes/cm^2, respectively. These features of CdS nanotubes enable more efficient carrier collection because of the reduced recombination, especially in those cases in which the minority carrier lifetime is short, thus resulting in a diffusion length of less than 100 nm. Nanotube CdS-CdTe solar cells exhibit a wide and strong spectral response and quantum efficiency, indicating enhanced light absorption and carrier generation and collection. Without the benefit of an antireflection coating, the cells exhibited a wide and strong spectral response of quantum efficiency, and a short current density of 25.5 mA/cm^2, an open circuit voltage of 750 mV, and a power conversion efficiency of 10.7% under 1-sun illumination. The materials and electro-optical characterizations indicated well-defined junction and interface behavior in these 3D nanotube solar cell configurations.
