A photovoltaic device comprising: a semiconductor substrate; a first amorphous semiconductor strip of a first conductivity type provided on one face of the semiconductor substrate; a second amorphous semiconductor strip of a second conductivity type, the second conductivity type being opposite to the first conductivity type, the second amorphous semiconductor strip being provided on the one face of the semiconductor substrate and located adjacent to the first amorphous semiconductor strip in an in-plane direction of the semiconductor substrate; wherein an i-type amorphous semiconductor layer is provided on the back face of the semiconductor substrate and the said first and second amorphous semiconductor strips (102n, 102p) are provided on the said i-type amorphous semiconductor layer; a plurality of electrodes spaced apart from each other and provided on at least one of the first and second amorphous semiconductor strips (102p, 102n); and a conductive part provided on the plurality of electrodes for electrically connecting the plurality of electrodes, characterized in that at least one of the first amorphous semiconductor strip and the second amorphous semiconductor strip has reduced-thickness regions, the reduced-thickness region is defined by a first point and a second point as measured along an in-plane direction of the first amorphous semiconductor strip or the second amorphous semiconductor strip, where the first point is the point on the first or second amorphous semiconductor strip (102p, 102n) with the maximum film thickness, and the second point is the point on the first or second amorphous semiconductor strip (102p, 102n) as measured along an in-plane direction at which the decreasing rate of the film thickness changes from a first decreasing rate to a second decreasing rate that is larger than the first decreasing rate or the value of the decreasing rate of the film thickness changes from negative to positive. a semiconductor substrate; a first amorphous semiconductor strip of a first conductivity type provided on one face of the semiconductor substrate; a second amorphous semiconductor strip of a second conductivity type, the second conductivity type being opposite to the first conductivity type, the second amorphous semiconductor strip being provided on the one face of the semiconductor substrate and located adjacent to the first amorphous semiconductor strip in an in-plane direction of the semiconductor substrate; wherein an i-type amorphous semiconductor layer is provided on the back face of the semiconductor substrate and the said first and second amorphous semiconductor strips (102n, 102p) are provided on the said i-type amorphous semiconductor layer; a plurality of electrodes spaced apart from each other and provided on at least one of the first and second amorphous semiconductor strips (102p, 102n); and a conductive part provided on the plurality of electrodes for electrically connecting the plurality of electrodes, characterized in that at least one of the first amorphous semiconductor strip and the second amorphous semiconductor strip has reduced-thickness regions, the reduced-thickness region is defined by a first point and a second point as measured along an in-plane direction of the first amorphous semiconductor strip or the second amorphous semiconductor strip, where the first point is the point on the first or second amorphous semiconductor strip (102p, 102n) with the maximum film thickness, and the second point is the point on the first or second amorphous semiconductor strip (102p, 102n) as measured along an in-plane direction at which the decreasing rate of the film thickness changes from a first decreasing rate to a second decreasing rate that is larger than the first decreasing rate or the value of the decreasing rate of the film thickness changes from negative to positive.