CN111987223B

CN111987223B - Application of ZIF-8 buffer layer in perovskite solar cell without electron transport layer

Info

Publication number: CN111987223B
Application number: CN202010906835.9A
Authority: CN
Inventors: 李亚峰; 王晶晶; 魏明灯
Original assignee: Fuzhou University
Current assignee: Fuzhou University
Priority date: 2020-09-02
Filing date: 2020-09-02
Publication date: 2023-04-18
Anticipated expiration: 2040-09-02
Also published as: CN111987223A

Abstract

The invention discloses an application of a ZIF-8 buffer layer in a perovskite solar cell without an electron transport layer, wherein the ZIF-8 buffer layer is deposited on ITO (indium tin oxide), and then the perovskite light absorption layer is prepared and finally used for assembling the perovskite solar cell. A layer of MOF material ZIF-8 is added between the conductive glass and the perovskite layer, and due to the specific mesoporous structure of the MOF material ZIF-8, a channel can be provided for electron transmission, and the generation of leakage current is reduced. The buffer layer ZIF-8 has the characteristics of simple preparation, high purity, relatively high short-circuit current of the solar cell and the like, so that the preparation process of the perovskite solar cell is further optimized, and the cost is reduced.

Description

Application of ZIF-8 buffer layer in perovskite solar cell without electron transport layer

Technical Field

The invention belongs to the field of solar cells, and particularly relates to an application of a ZIF-8 buffer layer in a perovskite solar cell without an electron transport layer.

Background

Perovskite solar cells have attracted the interest of many researchers due to their low cost, simple fabrication process, and all-solid-state characteristics. In less than ten years, the photoelectric conversion efficiency of the solar cell exceeds 25 percent, and the solar cell is expected to become a new generation of novel high-efficiency solar cells for large-scale commercial production. The traditional perovskite solar cell comprises three structures, namely a mesoporous structure, a planar heterojunction structure and a trans-structure. Either structure is generally composed of an Electron Transport Layer (ETL), a perovskite light absorption layer, a Hole Transport Layer (HTL), an electrode material, and the like. In order to further shorten the cost and simplify the process, in recent years, perovskite solar cells without the HTL are prepared, and good effects are achieved. Mei et al prepared lead-based perovskite, HTL-free devices with methylamine and 5-aminopentanoic acid as mixed cations with efficiencies up to 12.8%. The preparation of devices without ETL is only rarely reported, mainly because if a perovskite layer is directly deposited on conductive glass, leakage current and charge recombination are easily caused, and the photoelectric property of the battery is greatly reduced. Therefore, the perovskite solar cell without the ETL is necessary to be prepared under the condition of reducing the leakage current as much as possible, and has important significance for further promoting the commercial development of the perovskite solar cell. From the current research results, there are few reports on solving the leakage current problem of ETL-free perovskite solar cells. A layer of MOF material ZIF-8 is added between conductive glass and a perovskite layer, and due to a special mesoporous structure of the MOF material ZIF-8, a channel can be provided for electron transmission, and generation of leakage current is reduced.

At present, no relevant patent report of the application of a ZIF-8 buffer layer in a perovskite solar cell without an electron transport layer exists.

Disclosure of Invention

The invention aims to provide an application of a ZIF-8 buffer layer in a perovskite solar cell without an electron transport layer. ZIF-8 is deposited on the ITO by a simple solution soaking method, and then a perovskite light absorption layer is prepared and finally used for assembling the perovskite solar cell.

In order to realize the purpose, the invention adopts the following technical scheme:

the application of the ZIF-8 buffer layer in the perovskite solar cell without the electron transport layer is as follows: depositing a ZIF-8 buffer layer on the ITO, then preparing a perovskite light absorption layer, and finally assembling the perovskite solar cell.

The preparation method of the perovskite solar cell without the electron transport layer comprises the following steps: 0.4 mmol of Zn (NO) ₃ ) ₂ And 0.8 mmol of 2-methylimidazole is dissolved in 100 ml of methanol, the mixture is stirred for 60 min, then clean ITO is put into the solution and soaked for 40 min, after the soaking is finished, the substrate is dried at 70 ℃ to obtain a ZIF-8 buffer layer, then a perovskite layer and a hole transport layer are prepared on the ZIF-8 buffer layer, and finally, gold electrodes are plated to assemble the perovskite solar cell without the electron transport layer for testing the photoelectric property.

The invention has the advantages and the purposes that: a layer of MOF material ZIF-8 is added between the conductive glass and the perovskite layer, and due to the specific mesoporous structure of the MOF material ZIF-8, a channel can be provided for electron transmission, and the generation of leakage current is reduced. The buffer layer ZIF-8 has the characteristics of simple preparation, high purity, relatively high solar cell short-circuit current and the like, so that the preparation process of the perovskite solar cell is further optimized, and the cost is reduced. The invention provides a preparation method of a perovskite solar cell without an electron transport layer by using a ZIF-8 buffer layer for the first time. The method is novel, the preparation process is simple, and the method has good commercial application development prospect.

Drawings

FIG. 1 is an XRD pattern of an experimentally synthesized ZIF-8;

FIG. 2 shows Zn associated with ZIF-8 deposition on ITO ²⁺ High power XPS spectra of ions;

FIG. 3 is a scanning electron micrograph of ZIF-8 deposited on ITO;

FIG. 4 is a graph of the photovoltaic performance of a ZIF-8 buffer layer-based preparation of a perovskite solar cell without an electron transport layer.

Detailed Description

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below. The method of the present invention is a method which is conventional in the art unless otherwise specified.

Example 1

A preparation method of a perovskite solar cell without an electron transport layer comprises the following steps: 0.4 mmol of Zn (NO) ₃ ) ₂ Dissolving 0.8 mmol 2-methylimidazole in 100 ml methanol, stirring for 60 min, adding clean ITO into the solution, soaking for 40 min, drying the substrate at 70 ℃ after soaking to obtain a ZIF-8 buffer layer, and preparing CH on the ZIF-8 buffer layer ₃ NH ₃ PbI ₃ And finally, plating gold on the electrodes, and assembling the perovskite solar cell without the electron transport layer for testing the photoelectric property. Wherein the thickness of the ZIF-8 buffer layer is 20 nm, the thickness of the perovskite layer is 500 nm, the thickness of the spiro-OMeTAD hole transport layer is 100 nm, and the thickness of the gold electrode is 80 nm.

Comparative example 1

A preparation method of a perovskite solar cell without an electron transport layer and without ZIF-8 deposition specifically comprises the following steps: preparation of CH directly on ITO substrate ₃ NH ₃ PbI ₃ And finally, plating gold on the electrodes, and assembling the perovskite solar cell without the electron transport layer for testing the photoelectric property. Wherein the thickness of the perovskite layer is 500 nm, the thickness of the spiro-OMeTAD hole transport layer is 100 nm, and the thickness of the gold electrode is 80 nm.

The perovskite solar cell without the electron transport layer prepared on the basis of undeposited ZIF-8 is obtainedJ _SC Is 3.99mA/cm ² ，V _OC The photoelectric property parameter is 0.79V, the FF is 0.50, and the highest photoelectric conversion efficiency is 1.59 percent; whereas the perovskite solar cell without electron transport layer prepared using the ZIF-8 deposition in example 1 was obtainedJ _SC Is 14.45mA/cm ² ，V _OC The cell performance parameter is 0.95V, the FF is 0.52, the maximum photoelectric conversion efficiency is 7.09%, and the photoelectric performance of the cell prepared based on the ZIF-8 deposition is greatly improved, because the ZIF-8 deposition can reduce the generation of leakage current and is beneficial to the photoelectric performance of the cell.

If the ZIF-8 is carbonized and then used for preparing the perovskite solar cell, the ZIF-8 is converted into ZnO, and the alkalinity of the ZnO can induce the deprotonation reaction of organic amine ions, so that the perovskite thin film deposited on the ZnO is easily decomposed by heating, and the improvement and the stability of the device efficiency are limited.

FIG. 1 is an XRD pattern of ZIF-8, with diffraction peaks well matched to reported literature, indicating that the sample synthesized is pure phase ZIF-8. FIG. 2 is a ZIF-8 deposition on ITO for Zn ²⁺ The XPS spectrum of ions with high power shows two signal peaks at the binding energy of 1045.1 eV and 1022.01 eV, and the two signal peaks are respectively assigned to Zn by comparing with reported literature ²⁺ The ions are in transition signals of 2p1/2 and 2p3/2 energy level electrons, which means that a layer of ultra-thin ZIF-8 is successfully deposited on the surface of the ITO thin film by a solution soaking method. FIG. 3 is a scanning electron micrograph of ZIF-8 deposited ITO, showing thatLayer ZIF-8, which is applied over the entire membrane layer. As shown in FIG. 4, at 100 mW/cm ² Under the conditions of light intensity and AM1.5, the perovskite solar cell without the electron transport layer prepared on the basis of the ZIF-8 buffer layer is obtainedJ _SC Is 14.45mA/cm ² The short-circuit current of (a) is,V _OC the photoelectric conversion efficiency is 7.09 percent, and the photoelectric performance parameter is 0.95V, and the FF is 0.52.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.

Claims

1. The application of the ZIF-8 buffer layer in the perovskite solar cell without the electron transport layer is characterized in that the ZIF-8 buffer layer is deposited on ITO, and then the perovskite light absorption layer is prepared and finally used for assembling the perovskite solar cell; the ZIF-8 is of a mesoporous structure, provides a channel for electron transmission and reduces leakage current;

the method specifically comprises the following steps: 0.4 mmol of Zn (NO) ₃ ) ₂ And 0.8 mmol of 2-methylimidazole are dissolved in 100 ml of methanol and stirred for 60 min, then clean ITO is put into the solution and soaked for 40 min, after soaking is finished, the solution is dried at 70 ℃ to obtain a ZIF-8 buffer layer, then a perovskite layer and a hole transport layer are prepared on the ZIF-8 buffer layer, finally, gold electrodes are plated, and the perovskite solar cell without the electron transport layer is assembled, wherein the highest photoelectric conversion efficiency of the perovskite solar cell is 7.09%.