This paper reviews results of studies on different materials and technologies for monograin layer (MGL) solar cells conducted at Tallinn University of Technology. The MGL consists of monograin powder crystals embedded into an organic resin. The MGL combines the superior photoelectrical parameters of single crystals with the advantages of polycrystalline materials, such as the low cost and simple technology of materials and layers preparation and the possibility of making devices of practically unlimited area. A main technological advantage is the separation between absorber and cell formations. The developments in the field of monograin materials of CulnSe(2), Cu(2)ZnSnS(4) and Cu(2)ZnSnSe(4) and technical parameters of MGL. solar cells are summarized. (C) 2008 Elsevier B.V. All rights reserved.