A solar cell comprising a crystalline silicon substrate, a semiconductor layer arranged on a back surface of the substrate which is configured not to face a radiative source, when the solar cell is in use, and a transparent-conductive region arranged on a surface of the semiconductor layer, wherein the transparent conductive region comprises: a first layer having a first work function; and a second layer having a second work function and being interposed between the first layer and the semiconductor layer; wherein the second work function of the second layer is greater than the first work function of the first layer.

Provided is a photoelectric conversion element capable of suppressing a decrease in strength. A photoelectric conversion element comprises: a photoelectric conversion layer (26); an electrode layer (24) adjacent to the photoelectric conversion layer; a collecting electrode (30) adjacent to the electrode layer; and a conductor (50) joined to the collecting electrode. The thickness of the collecting electrode (30) at least at a joint portion between the collecting electrode (30) and the conductor (50) is 4 m or more.

A photovoltaic device includes a plurality of photovoltaic cells coupled in series, the photovoltaic cells including a first contact layer disposed over a first substrate, a first charge transport layer (CTL) disposed over the first contact layer, an absorber layer disposed over the first CTL, a second CTL disposed over the absorber layer, and an ultraviolet (UV) blocking layer comprising a first layer formed on a first side of the first substrate and a second layer formed over the first layer, wherein a refractive index (RI) between the first layer and the first substrate is less than or equal to 1.3, and an RI between the second layer and the first layer is from about 0.75 and about 1.5.

A heterojunction solar cell and a preparation method therefor. The heterojunction solar cell comprises: a semiconductor substrate layer; and a back composite transparent conductive film located on one side of the semiconductor substrate layer. The back surface composite transparent conductive film comprises: a first back surface transparent conductive film; and a second back transparent conductive film located on the side surface of the first back transparent conductive film facing away from the semiconductor substrate layer. Both the first back transparent conductive film and the second back transparent conductive film are doped with group III heavy atoms, and the concentration of the group III heavy atoms in the second back transparent conductive film is less than that of the group III heavy atoms in the first back transparent conductive film.

An ultra-speed photodetector includes a substrate, a light-absorbing layer, and a light-transmitting electrode layer. The light-absorbing layer located on the substrate. The electrode disposed on the light-absorbing layer and divided into a plurality of first electrodes and a plurality of second electrodes. A polarity of the first electrode is opposite to a polarity of the second electrode. The plurality of first electrodes arranged at intervals, and the second electrode located between the two adjacent first electrodes. A gap located between the first electrode and the second electrode that were adjacent to each other, and a portion of a surface of the light-absorbing layer exposed at the gap.