A temperature-induced method for deep doping of hole dopants at low concentrations

Abstract

The invention discloses a method for deep doping of a temperature-induced hole dopant at a low concentration. The preparation process of a hole transport layer in a perovskite solar cell structure is as follows: the material of the hole transport layer and TBAPF 6 Co-dissolved in dichloromethane to obtain hole transport layer material solution, hole transport layer material solution TBAPF 6 The mass concentration is 1‑4 wt%, and the hole transport layer is prepared on the perovskite film with the corresponding spin coating parameters; the obtained n‑i‑p type perovskite solar cell is subjected to low-temperature heating treatment, and then naturally cooled to room temperature. The present invention adopts TBAPF 6 Doping the material of the hole transport layer as a hole dopant, and performing low-temperature heating treatment on the prepared perovskite solar cells can effectively improve the 6 Photovoltaic performance and stability of solar cells prepared with doped hole transport layer materials.

Description

technical field [0001] The invention belongs to the technical field of perovskite solar cells, and in particular relates to a method for deep doping of a temperature-induced hole dopant at a low concentration. Background technique [0002] In recent years, organic-inorganic hybrid perovskite solar cells have been widely studied due to their low cost, solutionability and flexible processing, and their device efficiencies have soared. 2,2',7,7'-Tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) is the One of the most widely used hole-transporting materials, n-i-p-type perovskite solar cells need to be doped with traditional hole dopants 4-tert-butylpyridine (tBP) and lithium bistrifluoromethanesulfonimide (Li-TFSI). Among them, Li-TFSI can significantly improve the conductivity and hole mobility of the Spiro-OMeTAD thin film layer, but the introduction of Li-TFSI brings the following problems: (1) Li-TFSI is easy to deliquescence so that the prepared ...

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Problems solved by technology

2,2',7,7'-Tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) is the One of the most widely used hole-transporting materials, n-i-p-type perovskite solar cells need to be doped with traditional hole dopants 4-tert-butylpyridine (tBP) and lithium bistrifluoromethanesulfonimide (Li-TFSI). Among them, Li-TFSI can significantly improve the conductivity and hole mobility of the Spiro-OMeTAD thin film layer, but the introduction of Li-TFSI brings the following problems: (1) Li-TFSI is easy to deliquescence so that the prepared The Spiro-OMeTAD film has many holes, which will accelerate the decomposition of perovskite and reduce the performance and stability of the prepared device; (2) Li-TFSI has low solubility in organic solvents such as chlorobenzene and chloroform, so it is easy to Accumulation in Spiro-OMeTAD thin films, and Spiro-OMeTAD is also easy to aggregate and crystallize, which is not conducive to hole transport and thus affects the photoelectric performance of corresponding solar cells; (3) Li + Migrate from the hole transport layer to other layers of the perovskite solar cell, thereby affecting the stability of the device

The above problems will seriously affect the stability of the prepared solar cells, thereby limiting the further application of perovskite solar cells. Therefore, how to solve the above problems to achieve long-term stable storage and use of perovskite solar cells is very important

[0003] At present, the means of deeply doping the material of the hole transport layer mainly include increasing the concentration of hole dopants, oxidation by air or oxidizing substances, and mixing of various hole dopants. How to reduce the doping concentration Obtaining the deep doping effect is a direction worthy of research, but there is no report on the temperature-induced deep doping of hole dopants in low-concentration solar cells in the prior art.

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