Tunable hysteresis effect for perovskite solar cells

Advanced Energy Materials

et al. 2019

The rich molecular design of electron donor (D)–acceptor (A) polymers offers many valuable clues to obtain high‐efficiency hole‐transporting materials (HTMs) for use in perovskite solar cells (PVSCs). The fused aromatic or heteroaromatic units can increase the conjugation of the polymer backbone to facilitate electron delocalization, which increases the rigidity of adjacent units to prevent rotational disorder and lower the reorganization energy, leading to improved carrier mobility and optimized film morphology. In this work, fused‐ring ladder‐type indacenodithiophene and indacenodithieno[3,2‐b]thiophene are used as D units, benzodithiophene‐4,8‐dione as the A unit, and thienothiophene as a π‐bridge to form the D–A polymers PBDTT and PBTTT, respectively. Both polymers exhibit favorable properties as HTMs including suitable energy levels, high hole mobility, and excellent film quality. Both dopant‐free HTMs endow n‐i‐p PVSCs with promising performance and stability. A maximum power conversion efficiency of 20.28% is achieved for PBDTT‐based devices, which is among the highest values reported to date.

Section: Resultsmentioning

confidence: 99%

Dopant‐Free, Donor–Acceptor‐Type Polymeric Hole‐Transporting Materials for the Perovskite Solar Cells with Power Conversion Efficiencies over 20%

You

Zhuang

Advanced Energy Materials

et al. 2019

“…[1,2] Noticeably, very few studies have been reported regarding their potential to indoor applications for low power consumption wireless electronics such as Internet of Things (IOT) and self-sustainable smart housing. [1,2] Noticeably, very few studies have been reported regarding their potential to indoor applications for low power consumption wireless electronics such as Internet of Things (IOT) and self-sustainable smart housing.…”

Section: Introductionmentioning

confidence: 99%

Interface Modification by Ionic Liquid: A Promising Candidate for Indoor Light Harvesting and Stability Improvement of Planar Perovskite Solar Cells

Zhao

Advanced Energy Materials

et al. 2018

202

107

Organic–inorganic hybrid perovskite solar cells (PSCs) are currently attracting significant interest owing to their promising outdoor performance. However, the ability of indoor light harvesting of the perovskites and corresponding device performance are rarely reported. Here, the potential of planar PSCs in harvesting indoor light for low‐power consumption devices is investigated. Ionic liquid of 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([BMIM]BF4) is employed as a modification layer of [6,6]‐phenyl‐C61‐butyric acid methyl ester) (PCBM) in the inverted PSCs. The incorporation of [BMIM]BF4 not only paves the interface contact between PCBM and electrode, but also facilitates the electron transport and extraction owing to the efficient passivation of the surface trap states. Moreover, [BMIM]BF4 with excellent thermal stability can act as a protective layer by preventing the erosion of moisture and oxygen into the perovskite layer. The resulting devices present a record indoor power conversion efficiency (PCE) of 35.20% under fluorescent lamps of 1000 lux, and an impressive PCE of 19.30% under 1 sun illumination. The finding in this work verifies the excellent indoor performance of PSCs to meet the requirements of eco‐friendly economy.

“…[1][2][3][4][5][6][7][8][9][10] In this regard, the selection of materials is of fundamental importance for www.advelectronicmat.de carriers of the silicon substrate and bound surface charges of the BST thin film. [1][2][3][4][5][6][7][8][9][10] In this regard, the selection of materials is of fundamental importance for www.advelectronicmat.de carriers of the silicon substrate and bound surface charges of the BST thin film.…”

Section: Introductionmentioning

confidence: 99%

“…Due to their unique electronic and optical characteristics, 2D and quasi-2D materials are emerging as exciting material systems for a new generation of layered optoelectronics, [11,12] such as photodetectors, [13,14] polarizers, [15] solar cells, [3,[16][17][18] and optical modulators. Due to their unique electronic and optical characteristics, 2D and quasi-2D materials are emerging as exciting material systems for a new generation of layered optoelectronics, [11,12] such as photodetectors, [13,14] polarizers, [15] solar cells, [3,[16][17][18] and optical modulators.…”

mentioning

confidence: 99%

Multifield‐Inspired Tunable Carrier Effects Based on Ferroelectric‐Silicon PN Heterojunction

Lou

et al. 2019

Adv Elect Materials

the entire modulation process. Due to their unique electronic and optical characteristics, 2D and quasi-2D materials are emerging as exciting material systems for a new generation of layered optoelectronics, [11,12] such as photodetectors, [13,14] polarizers, [15] solar cells, [3,[16][17][18] and optical modulators. [19,20] For instance, graphene has many intriguing mechanical, electronic, thermal, and optical properties because the electrons behave as massless Dirac fermions and exhibit the highest mobility. [21,22] 2D transition-metal dichalcogenides (TMDs) change from indirect semiconductors to direct semiconductors when thinned to monolayers, showing remarkable optoelectronic properties. [23] The formation mechanism of traditional carrier layers is usually based on the high carrier mobility of 2D and quasi-2D materials. Although significant progress has been achieved through years of research, the preparation technology of new 2D materials, such as graphene and monolayer TMDs, is not mature and stable. To meet the demand for large-scale preparation of 2D materials with stable performance, improving the preparation technology, exploring new design mechanisms, or seeking other stable materials as candidates is urgent.Ferroelectrics are such stable materials with simple preparation methods. Additionally, the domains can be controlled via electric, thermal, optical, and mechanical fields, [24][25][26][27][28] meaning that the bound surface charges of ferroelectrics can be modulated under single-field or multifield coupling. Inspired by the PN heterojunction effect, in which the generation of current carriers in the space charge region can be extremely high, [29][30][31][32][33][34][35] combining ferroelectrics and semiconductors with high carrier mobility to construct PN heterojunctions may be an effective way to form a carrier layer and achieve carrier modulation.To demonstrate this concept, N-type silicon with a bandgap of 1.12 eV is chosen as the semiconductor material, which can guarantee sufficient free electrons under optical field. Ferroelectrics usually have a Curie temperature T 0 above which they are in a paraelectric phase state. Due to its good dielectric performance with significant dielectric nonlinearity over a wide temperature range near T 0 , Ba 0.7 Sr 0.3 TiO 3 (BST) thin film is chosen as the ferroelectric material. By depositing the BST thin film directly onto a silicon substrate, the BST-silicon PN heterojunction is constructed, deriving from the interaction between