NOVELTY - Fabricating monolithically-integrated optoelectronic modules (100), comprises: (a) depositing an electrically conductive layer (120) onto an insulating layer (110) or onto a semiconductive layer (130, 140); (b) depositing at least one semiconductive layer (130, 140) onto a layer (120, 150) deposited in the previous step (a); and (c) depositing at least one conductive front-contact layer (150) onto the layer (130, 140) deposited in the previous step (b) or onto the insulating layer (110).    USE - The method is useful for fabricating monolithically-integrated optoelectronic modules (claimed).    ADVANTAGE - The method is cost effective, has higher production and efficiently fabricates improved monolithically-integrated optoelectronic modules.    DETAILED DESCRIPTION - Fabricating monolithically-integrated optoelectronic modules (100) comprising at least two series-interconnected optoelectronic components (104, 106), such as photovoltaic, diode, or light-emitting diode components, starting from an initial electrically insulating layer (110) positioned either as a substrate under, or as a superstrate on top of, a stack of layers produced by the following steps conducted in the order (a), (b), (c) if the initial insulating layer is positioned for a substrate configuration, or in the order (c), (b), (a) if the initial insulating layer is positioned for a superstrate configuration, the method comprises producing the stack of layers by the steps of: (a) depositing an electrically conductive layer (120), called the back-contact layer, onto the insulating layer (110) or onto the semiconductive layer (130, 140) from step (b); cutting at least one groove (121), herein called back-contact groove, into the back-contact layer (120) so as to expose at least one continuous line of the insulating layer (110) or of the semiconductive layer (130, 140), thus providing at least one first and at least one second back-contact component (122, 124, 126, 128) that are electrically disconnected; (b) depositing at least one semiconductive layer (130, 140), including at least one semiconductive optoelectronically active layer (130), onto the layer (120, 150) deposited in the previous step (a) or (c), thus filling the grooves (121, 151), and where the semiconductive optoelectronically active layer (130) is for example made of cadmium telluride (CdTe) or of an ABC2 material, where A represents elements in group 11 of the periodic table of chemical elements as defined by the International Union of Pure and Applied Chemistry including copper (Cu) and silver (Ag), B represents elements in group 13 of the periodic table including indium (In), gallium (Ga) and aluminum (Al), and C represents elements in group 16 of the periodic table including sulfur (S), selenium (Se) and tellurium (Te); (c) depositing at least one conductive front-contact layer (150) onto the layer (130, 140) deposited in the previous step (b) or onto the insulating layer (110); cutting at least one groove (151) in it, called front-contact groove, into the front-contact layers (150), such as to expose at least one continuous line of the layer (130,140) deposited in the previous step or the insulating layer (110), thus providing at least one first and at least one second front-contact component (154, 156, 158) that are electrically disconnected, the first and second front-contact components (154, 156, 158) comprising parts that overlie corresponding first and second back contact components (122, 124, 126, 128); the method further comprises the step, for at least one of the second back-contact components (124, 126), of drilling at least one cell-to-cell via hole (155) through layers deposited at steps (b) and (c) such that the cell-to-cell via hole (155) exposes part of the back contact layer (120) and/or the insulating layer (110), using a drilling process that generates heat such that heat of the drilling process causes a permanent change in the chemical composition of the surface of the cell-to-cell via hole (155) within the semiconductive layers (130, 140) by causing a surface metallization (134, 136) so that the surface of the cell-to-cell via hole (155) becomes electrically conductive, to establish an electrical path between at least one of the first front-contact components (154, 156) and at least one corresponding second back-contact component (124, 126), thus realizing at least two series-interconnected optoelectronic components (104, 106). An INDEPENDENT CLAIM is a monolithically-integrated optoelectronic module apparatus (100).    DESCRIPTION OF DRAWING(S) - The drawing shows a cross sectional view of a monolithic photovoltaic module.    Optoelectronic components (104, 106, 108)    Substrate or superstrate (110)    Back-contact electrode (122)    Semiconductive layer (130)    Semiconductive layer's surface (134, 136, 138)    Buffer layer (142)    Front-contact components (152, 154, 156, 158)    Metallized front-contact grid components (164, 166, 168)