NOVELTY - Encapsulant material with enhanced light reflectivity comprises a porous structure, where an average pore diameter of the porous structure being between several hundreds of nanometers and several hundreds of micrometers, so as to improve the light reflectivity of the encapsulant material, and the encapsulant material is crosslinked by a chemical or physical crosslinking method, so as to improve heat resistance of the encapsulant material.    USE - The encapsulant material is useful in the crystalline silicon photovoltaic module and the thin film photovoltaic module (all claimed).    ADVANTAGE - The encapsulant material has improved light reflectivity and heat resistance.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a crystalline silicon photovoltaic module (100) comprising a first backsheet (102), a first encapsulant layer (104), many crystalline silicon solar cells, a second encapsulant layer (108) and a transparent substrate (110) sequentially stacked, in which the crystalline silicon photovoltaic module further comprises the encapsulant material with porous structure disposed between the backsheet and the transparent substrate, so as to collect light passing through a gap between the crystalline silicon solar cells and to increase power conversion efficiency of the crystalline silicon photovoltaic module; and    (2) a thin film photovoltaic module comprising a backsheet, a back electrode transparent conductive layer, a thin film solar cell, a transparent conductive layer and a transparent substrate sequentially stacked, in which the thin film photovoltaic module further comprises an encapsulant material with porous structure disposed between the backsheet and the back electrode transparent conductive layer, so as to enhance light absorption in the thin film solar cell, thus enhancing power conversion efficiency of the thin film photovoltaic module.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic cross-sectional view of a crystalline silicon photovoltaic module.    Crystalline silicon photovoltaic module (100)    First backsheet (102)    First encapsulant layer (104)    Second encapsulant layer (108)    Transparent substrate. (110)