Perovskite solar cell modified by chelating layer and its preparation method
The invention relates to a perovskite solar cell modified by a chelating layer and its preparation method, within the field of perovskite material preparation. The process involves spin-coating N, N′-bis(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic diimide (DPNDI) solution on the perovskite surface, followed by annealing. This modification forms a chelating structure on the surface, passivating defect sites and grain boundaries, promoting charge transfer with optimized energy levels and carrier mobility. The Pb (II) coordination polymer layer enhances bonding strength and adhesion, effectively suppressing traps. The treated perovskite solar cell achieves a photoelectric conversion efficiency (PCE) of 24.2%, with a T80 lifetime retaining over 95% (40° C.) and 85% (85° C.) of the initial PCE after 2000 hours. This modified film inhibits ion migration, providing enhanced stability and high photoelectric conversion efficiency in optoelectronic devices.
1 . A preparation method for a perovskite solar cell modified by a chelating layer, comprising:
spin-coating N,N′-bis(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic diimide (DPNDI) solution on a surface of a halide perovskite of the perovskite solar cell and annealing the surface;
using a strong coordination ability of pyridine with metal ions in a perovskite layer, packaging the pyridine with an end group of DPNDI molecule on a perovskite surface to form a Pb (II) coordination polymer with strong chemical bond, so as to passivate surface defects of the halide perovskite and promote an effect of interface charge transfer, thereby improving a photoelectric conversion efficiency and an operational stability of the perovskite solar cell.
2 . The preparation method for the perovskite solar cell modified by the chelating layer according to claim 1 , the perovskite comprising all two-dimensional (2D) and three-dimensional (3D) halide perovskites;
a structure of a 2D halide perovskite is A′ m A n−1 B n X 3n+1 , wherein A′ represents a monovalent or divalent organic cation that separates one group of perovskite layers from another group of perovskite layers, and n is an integer of at least 1 denoting a number of perovskite layers between A′ organic layers; A is one or more of cesium (Cs), methylammonium (MA), formamidinium (FA), B is one or more of Pb, Sn, Ge, and X is one or more of I, Br, Cl, F; and
a structure of a 3D halide perovskite is ABX 3 , wherein A is one or more of Cs, MA and FA, B is one or more of Pb, Sn and Ge, and X is one or more of I, Br, Cl and F.
3 . The preparation method for the perovskite solar cell modified by the chelating layer according to claim 1 , wherein the DPNDI solution comprises a solvent selected from one or more of chlorobenzene, ethyl acetate, and anisole; wherein a concentration of the DPNDI solution is 1-10 mg/mL.
4 . The preparation method for the perovskite solar cell modified by the chelating layer according to claim 1 , wherein, a spin-coating speed is 1000-10000 rpm.
5 . The preparation method for the perovskite solar cell modified by the chelating layer according to claim 1 , wherein, an annealing temperature is 30-200° C., and an annealing time is 1-10 min.
6 . The preparation method for the perovskite solar cell modified by the chelating layer according to claim 1 , wherein a core functional layer of the perovskite solar cell is one selected from a formal structure and an inverted structure, an arrangement order of the formal structure is an electron transport layer, a perovskite light-absorption layer and a hole transport layer from bottom to top; an arrangement order of the inverted structure is a hole transport layer, a perovskite light-absorption layer and an electron transport layer from bottom to top.
7 . The preparation method for the perovskite solar cell modified by the chelating layer according to claim 6 , wherein a chelating structure is formed on the surface of the halide perovskite of the perovskite solar cell, and wherein the chelating structure passivates defect sites at a surface and grain boundaries, and has appropriate energy level and carrier mobility to promote interface charge transfer; and the Pb (II) coordination polymer with strong chemical bond improves bonding strength and adhesion of the surface, which shows a strong trap suppression ability.