Impurity diffusion layer forming composition, method of manufacturing semiconductor substrate having impurity diffusion layer, and method of manufacturing solar cell element

Provided is an impurity diffusion layer forming composition which contains: a compound having a donor element or a compound having an acceptor element; a dispersion medium; and a compound represented by general formula (I). In general formula (I), R 1 and R 2 independently represent a hydrogen atom or an alkyl group, and R 3 represents an alkylene group. n represents an arbitrary integer greater than or equal to 1.