Tandem cell, method for preparing the same, and photovoltaic module

A tandem cell, comprising:

• a bottom cell, wherein the bottom cell comprises;
• a substrate, the substrate has a first side and a second side opposite to the first side, the first side has a first textured surface including at least one first protrusion structure, the second side has a textured surface including a plurality of protrusion structures, and the plurality of protrusion structures have a same dimension as that of the at least one first protrusion structure;
• a tunneling dielectric layer formed on the second side, the tunneling dielectric layer is conformal to the textured surface of the second side;
• and
• a doped conductive layer formed on the tunneling dielectric layer, wherein the doped conductive layer has a micro textured surface away from the tunneling dielectric layer, the micro textured surface comprises at least one micro protrusion structure, and the at least one micro protrusion structure is smaller than the at least one first protrusion structure;
• a composite layer formed on the doped conductive layer, wherein the composite layer is conformal to the micro textured surface;
• and
• a top cell formed on the composite layer, wherein the top cell comprises a first transport layer, a perovskite substrate having a first surface facing the bottom cell and an opposing second surface, a second transport layer, a transparent conductive layer, and an anti-reflection layer stacked sequentially, the first transport layer is between the composite layer and the perovskite substrate, and the first transport layer is conformal to the micro textured surface and the first surface of the perovskite substrate is conformal to the first transport layer.