Intrinsic and Extrinsic Charge Transport in CH3NH3PbI3 Perovskites Predicted from First-Principles

Abstract

Both intrinsic and extrinsic charge transport properties of methylammonium lead triiodide perovskites are investigated from first-principles. The weak electron-phonon couplings are revealed, with the largest deformation potential (~ 5 eV) comparable to that of single layer graphene. The intrinsic mobility limited by the acoustic phonon scattering is as high as a few thousands cm2 V−1 s−1 with the hole mobility larger than the electron mobility. At the impurity density of 1018 cm−3, the charged impurity scattering starts to dominate and lowers the electron mobility to 101 cm2 V−1 s−1 and the hole mobility to 72.2 cm2 V−1 s−1. The high intrinsic mobility warrants the long and balanced diffusion length of charge carriers. With the control of impurities or defects as well as charge traps in these perovskites, enhanced efficiencies of solar cells with simplified device structures are promised.

Electron–acoustic phonon coupling in single crystal CH3NH3PbI3 perovskites revealed by coherent acoustic phonons

“…Extrinsic factors, such as defects, are sample dependent, while intrinsic are properties of the material. Understanding of the electron-lattice coupling and its importance for charge transport has, therefore, attracted a lot of attention in recent years511121314151617. Despite this intense scrutiny, a consensus concerning charge transport has still not been reached.…”

“…Multiple theoretical studies have been devoted to obtaining the acoustic phonon limited mobility51617. High values, up to a few thousands of cm 2  V −1  s −1 , have been reported for both electron and hole mobilities, however, discrepancies exist between these reports regarding the relative contributions of holes and electrons to the overall mobilities517. Furthermore, due to the lack of experimental methods, there are, to our knowledge, no experimentally determined values of these intrinsic mobilities.…”

Electron-phonon coupling and polaron mobility in hybrid perovskites from first-principles

“…26,27 Here we briefly point out the differences with the polaron method used in this work. The main assumption of DPT is that electron/hole scattering is only limited by scattering to long-wavelength acoustic phonons.…”

Fabrication and characterization of perovskite solar cells added with MnCl2, YCl3 or poly(methyl methacrylate)

“…In addition to their efficient light absorption and high carrier mobility, they are semiconductors with adjustable band gaps, which have the benefits to absorb different wavelengths of light and to fit into the solar devices well [1][2][3][4][5][6][7][8][9]. Further control over the optical and magnetic properties of quantum dots can be achieved through doping of transition metal ions such as Mn 2+ or Co 2+ [10].…”