The invention relates to a multijunction thin film solar cell (70) of high efficiency and low-cost production. The n-layer (64, 65, 66, 67) of one of the constituent cells (61) of the multijunction thin film solar cell has a structure comprising, in the intended direction of impinging light, a sequence of an amorphous hydrogenated silicon n-layer (64), a first microcrystalline hydrogenated silicon n-layer (65), an intermediate reflector layer (66) and a second microcrystalline hydrogenated silicon n-layer (67), wherein the intermediate reflector layer is one of the following: - a single microcrystalline essentially silicon oxide layer; or - a plurality of layer sequences, each layer sequence consisting of a microcrystalline essentially silicon oxide layer and a microcrystalline silicon n-layer in the intended direction of impinging light. The invention further relates to methods of manufacturing the above n-layer (64, 65, 66, 67), and to methods of manufacturing the above-mentioned multijunction thin film solar cell (70).