Solar cell and production method thereof, photovoltaic module

A solar cell includes a P-type emitter 10 formed on a first surface of an N-type substrate 100 which may be an N-type silicon substrate and including a first portion 11 and a second portion 12. A top surface of the first portion includes first pyramid structures 1 and a top surface of the second portion includes second pyramid structures 2 whose edges are straight. A transition surface (Fig. 2; 13) is formed on at least one edge of each first pyramid structure, which is adjoined by two adjacent inclined surfaces of each first pyramid structure. The transition surface is concave or convex relative to a centre of each first pyramid structure, and the top surfaces of the first pyramid structures includes a spherical or spherical-like substructure (Fig 2: 14). A tunnel layer 150 and a doped conductive layer 160 are sequentially formed over a second surface of the N-type substrate to form a solar cell which may be configured as a tunnel oxide passivated contact (TOPCON) cell. A metal electrode 140 is electrically connected to the first portion 11 of the P-type emitter, which may be thicker than the second portion 12. The junction depth of the first portion may be deeper than that of the second portion. The sheet resistance of the first portion 11 of the P-type emitter is lower than that of the second portion 12, reducing the contact resistance between the metal electrode 140 and emitter 10, hence photoelectric conversion performance is enhanced. A photovoltaic module may comprise a cell string comprising plural solar cells (Fig. 6: 101).