Pentadiamond: A Highly Efficient Electron Transport Layer for Perovskite Solar Cells

Abstract

Rapid improvements in the power conversion efficiency of perovskite solar cells (PSCs), to as high as 25.5%, have aroused great interest in perovskite-based systems. Nevertheless, for achieving highly efficient photovoltaic performance, a persistent challenge lies in carrier extraction at the interface between the perovskite and electron transport layers, which requires that the electron transport material (ETM) should possess high carrier mobility and a small energy level offset with the perovskite. Herein, we find that pentadiamond, a new carbon phase, is a highly efficient ETM that could exhibit desirable photovoltaic performance by enhancing the interface carrier extraction. Based on first-principles calculations, pentadiamond displays a semiconducting nature with an indirect bandgap of 2.46 eV. A favorable band alignment at the pentadiamond/MAPbI3 interface demonstrates a large driving force for the interface electron transfer. Furthermore, the calculated electron mobility of pentadiamond can be as high as 351.72 cm2 s–1 V–1, thus highlighting its outstanding electron transport capability. Interestingly, the calculated transferred charge across the interface between MAPbI3 and pentadiamond reaches 1.29 electrons, indicating the rather high interface transport capacity. Such interesting findings feature pentadiamond as a highly efficient ETM with great prospects and applications in PSCs.

Unexpected low thermal expansion coefficients of pentadiamond

“…The lattice constants in the current work agree well with previous calculations. 16,17,21,23–25,46 The energy of pentadiamond is slightly higher than that of diamond, which is consistent with the original work 16 and the comment. 17 The agreement of the current work and previous work confirms the reliability of current settings.…”

“…In all the mentioned vibration modes, the vibration of C3 is out of the plane determined by the doublepentagon. Those modes can be divided into two classes: the one including TO 1 , TO 2 , LO 1 and LO 3 , is that two atoms in the shared edge vibrate to the same direction, and the other (LO 2 ) 16 9.184, 17 9.191, 17 9.19, 21 9.270, 25 9.153, 24 9.195, 46 9.179, 23 is that the two atoms vibrate to opposite directions. Structurally, when taking C2 and C3 as a whole, the double-pentagon can be simplified as a dumbbell (as Fig.…”

“…Recently, a new carbon allotrope, pentadiamond, was reported in the literature. 16 Though its mechanical properties are not as novel as in the original report, 17–19 pentadiamond still exhibits some exciting properties, including (1) high stability both mechanically and dynamically 16 and at high temperatures up to 1100 K, 20 (2) thermal conductivity of 428–490 W m −1 K −1 at room temperature, 21,22 comparable with that of pure copper, (3) high electrical conductivity, 23 and (4) good optical and thermoelectric properties. 24,25 In the present work, the LTEC of pentadiamond is predicted, being negative at low temperature and lower than that of diamond in the temperature range of 0 K to 2000 K. The mechanism of the low LTEC is presented.…”

Effects of Defect on Work Function and Energy Alignment of PbI2: Implications for Solar Cell Applications

“…Finally, we analyze the band alignment between pristine and defective PbI 2 together with other common PSCs materials like the MAPbI 3 , FAPbI 3 , and electron hole transport materials. Figure shows the alignment of the band edges, levels of point defects in PbI 2 , and other CBM/VBM of FAPbI 3 , MAPbI 3 , TiO 2 , SnO 2 , and ZnO from the literature. , Figure shows some possible interfaces formed between PbI 2 and MAPbI 3 , which have the potential to create a Schottky junction between p-type PbI 2 and perovskite MAPbI 3 . The values of the work function W of the perfect and defective ML-PbI 2 system are listed in Table .…”

Family of Two-Dimensional Transition Metal Dichlorides: Fundamental Properties, Structural Defects, and Environmental Stability

“…On the contrary, the difference in the electronegativity of Cl (3.0) and Cd (1.7), Mn (1.5), V (1.6), and Zn (1.6) is close to ∼1.5, which suggests the existence of ionic bonds between these compounds. To support this conclusion, the electron localization function for 2D FeCl 2 and 2D ZnCl 2 is analyzed. − In the case of 2D FeCl 2 (Figure S5a), the electron localization isobserved on Fe atoms and partially on the Fe–Cl bond, which confirm the existence of an ionocovalent type of bonding in 2D FeCl 2 . In the case of 2D ZnCl 2 (Figure S5b), the electron localization basin is spherical and completely migrates to the Zn atom so that basins are all surrounding the respective cores, suggesting an ionic bond in 2D ZnCl 2 .…”