A dopant-free hole-transporting material for efficient and stable perovskite solar cells

Liu, Jian; Wu, Yongzhen; Qin, Chuanjiang; Yang, Xudong; Yasuda, Takeshi; Islam, Ashraful; Zhang, Kun; Peng, Wenqin; Chen, Wei; Li, Han

doi:10.1039/c4ee01589d

Cited by 692 publications

(548 citation statements)

References 39 publications

Supporting

Mentioning

528

Contrasting

Unclassified

Order By: Relevance

“…[ 19 ] These dopants harm the device stability. [ 21 ] Some dopant-free organic HTMs showed good performance. Using pristine tetrathiafulvalene derivative TTF-1 as HTM, solar cells gave a PCE of 11.0%.…”

Section: Mesoporous Structurementioning

confidence: 99%

Advances in Perovskite Solar Cells

et al. 2016

View full text Add to dashboard Cite

widely commercialized, but possiblities to increase their performance are limited, because nowadays the so-called balance of systems (BoS) cost of PV modules makes up most of the cost. [ 1 ] As much of the BoS scales with area, performance improvement seems the only way to decrease the cost of PV power further. Therefore, new PV cells are sought either to allow for higher effi ciencies than what is possible with Si PV without cost increase, or, as explained in section 3.4, to provide lowcost added effi ciency to Si PV. Emerging solar cells such as dye-sensitized, bulkheterojunction and quantum-dot solar cells can be fabricated via low-temperature solution processing, that holds promise for low-cost large scale application, but best power conversion effi ciencies (PCE) are half of, or less than that of the best commercial Si PV cells. [ 2 ] This is where perovskite solar cells enter, as for the fi rst time in PV history it is possible to produce high-effi ciency cells at low monetary and energy costs, with apparent ease of fabrication from earth-abundant, readily available raw materials. The PCE for perovskite solar cells has increased from 2.2% to 20.1% since 2006, showing an inviting vista of commercialization. [ 3,4 ] Perovskite solar cells are named after the crystal structure of the light absorbers, the structure of the mineral CaTiO 3 . Many compounds with ABX 3 stoichiometry take this structure, where A and B are 12-and 8-coordinates cations, respectively, and X is the anion. [ 4 ] Of the many ABX 3 only few are suitable to be efficient light absorbers for solar cells due to requirements such as appropriate bandgap for good light-harvesting ability, energy level/band alignment with contacting materials, long charge carrier lifetime, τ, and high mobility, µ. Perovskites generally have divalent anions, and the strong electrostatic bonding mostly makes their (high) bandgaps not suitable for solar PV. Mitzi et al. initiated using perovskites containing halides, ammonium cations and Sn 2+ in optoelectronic devices, which formed the basis for the development of perovskites for solar cells. [ 5 ] Here we will focus on such halide perovskites, together with one divalent (Pb 2+ ) and one monovalent (mostly CH 3 NH 3 + ) cation. The most effi cient halide perovskite solar absorbers consist of organic ammonium ions (CH 3 NH 3 + or NH = CHNH 3 + ), Pb 2+ and halide ions (I − , Br − ).[ 4 ] CH 3 NH 3 PbI 3 possesses broad and intense light absorption. It is an ambipolar semiconductor (can be n-or p-type), and its charge carriers can have long diffusion lengths and lifetimes, which allow excellent PCE for solar cells made with it. [3][4][5][6] Another advantage of perovskite absorbers is the low-temperature solution-processing ability, which helps

show abstract

Section: Mesoporous Structurementioning

confidence: 99%

Advances in Perovskite Solar Cells

et al. 2016

View full text Add to dashboard Cite

show abstract

“…[255][256][257][258] We further note that the loss in performance is often related to the use of additives like Li-TFSI, tert-butylpyridine (tBP), and Co-complexes, necessary to oxidize the HTM and achieve high enough conductivities to ensure balanced charge extraction and maximum device performance. [259][260][261] Therefore, several HTMs have been developed that do not require these additives in order to obtain good performance. However, in general, devices without additives show lower PCEs than their counterparts containing the additives.…”

Section: Wwwadvancedsciencenewscommentioning

confidence: 99%

Capturing the Sun: A Review of the Challenges and Perspectives of Perovskite Solar Cells

Petrus

Schlipf

Cheng

et al. 2017

Advanced Energy Materials

317

201

View full text Add to dashboard Cite

following statement: These materials can be processed from solution and yet exhibit optoelectronic materials properties described in classic solid-state physics textbooks. This unprecedented combination has led to photovoltaic devices that can be processed at room temperature and achieve performance levels similar to industry giant polycrystalline silicon, from a starting point of 3.8% in 2009. [1][2][3][4] The first light-emitting electrochemical cells [5] and diodes [6][7][8] have also been introduced recently, leading to tunable light emission spectra and internal quantum efficiencies exceeding 15%.The road towards these achievements has been marked by a constant improvement of perovskite deposition techniques fueled by our increasing understanding of the crystallization processes. The choice of deposition technique, either from solution or vapor, and the composition and order in which precursor species are applied has a great influence on the crystallization kinetics. Here, one can distinguish one-step methods where the perovskite is formed from a precursor mixture dissolved in a common solution, and two-step methods where the inorganic compound is deposited first and transformed to the perovskite phase later by addition of the organic constituents. [9][10][11] Furthermore, many parameters during processing can have an effect on the crystallization mechanism and consequently on film morphology, such as the choice of solvents, concentrations and processing additives that are often not incorporated into the final product. [11][12][13] We discuss this aspect in Section 2, where we focus our attention on the most commonly employed solution-based techniques. Additionally, as for any new technology trying to displace an incumbent technology, higher efficiencies, lower costs, reproducibility, stability, and sustainability are paramount. In particular, reproducibility has been a major challenge in perovskite solar cells from the beginning: small variations in morphology, like crystal size, film roughness, and pinholes can have detrimental effects on photovoltaic performance. [14] On the other hand, current-voltage measurements often showed a hysteresis that is rarely seen in other photovoltaic technologies. [15] These topics are highlighted in Sections 3 and 4. Finally, in Section 5 we discuss the framework for market introduction, such as cost reduction by choosing low-cost charge transport layers, or how the lifetime of perovskite absorbers can be extended by the choice of materials composition.Hybrid metal halide perovskites have become one of the hottest topics in optoelectronic materials research in recent years. Not only have they surpassed everyone's expectations and achieved similar performance as tried and true polycrystalline silicon photovoltaic devices, but they are also finding applications in a variety of different fields, including lighting. The main advantages of hybrid metal halide perovskites are simple processability, compatible with large-scale solution processing such as roll-to-roll printing, a...

show abstract

“…[36] 与常规的钙钛矿太阳能电池相比, 这种无空穴传输材料型钙钛矿太阳能电池结构和制备工序更加简单, 在不使用 spiro-OMeTAD 等空穴传输材料的情况下, 器件的原材料成本将大大降低. 除此之外, 空穴收集层中所使用的 TBP、 LiTFSI 等添加剂会影响钙钛矿太阳能电池的稳定性 [81] , 尽管已有不需要进行掺杂处理的空穴传输材料的相关报道 [82,83] …”

Section: 无空穴传输材料型介观钙钛矿太阳能电池unclassified

“…Cross-sectional structure of hole-conductor-free fully printable mesoscopic perovskite solar cells based on carbon counter electrodes using spheroidal graphite (a) and flaky graphite (b) [39] 之后, Han 等采用 TiO 2 纳米片替代常规的 TiO 2 纳米颗粒作为光阳极, 制备出光电转换效率超过 10%的无空穴传输材料可印刷钙钛矿太阳能电池 [83] . 研究表明, TiO 2 纳米片更有利于 CH 3 NH 3 PbI 3 向电子收集层注入电子, 同时, 电子在传输过程中的复合反应也较小 [92] .…”

Section: Figure 18unclassified