Significant Enhancement in Optoelectronic Properties of γ-Cu_xAg_1–xI Films Induced by Highly (111)-Preferred Orientation and Cu Content at Room Temperature

Abstract

Crystallographic orientations play a crucial part in optoelectronic properties of crystalline materials. This paper reported significant enhancement of optoelectronic properties in γ-phase copper silver iodide (γ-Cu x Ag 1−x I, 0.6 ≤ x ≤ 0.9) films compared with Cu-poor (0.1 ≤ x ≤ 0.4) counterparts due to highly (111)-preferred orientation and larger grains. Transient surface photovoltage spectroscopy reveals that Cu x Ag 1−x I (0.6 ≤ x ≤ 0.9) exhibits faster transferring rate and slower recombination rate of charge carriers than Cu-poor ones. The preferred orientation significantly influenced the photoelectric properties by reducing photocarrier recombination. In X-ray diffraction patterns and Rietveld results, it was displayed that Cu x Ag 1−x I (x = 0.1−0.9) films exhibit (111)-preferred orientation and higher crystallinity when Cu doping content increased. Scanning electron microscope electron channeling contrast imaging analysis demonstrated (111) with most grains with larger size in Cu-rich films compared with Cu-poor films that were grown in the step flow growth mode from (111)-preferred prisms defined as basic units. This paper may provide a valuable basis for Cu x Ag 1−x I with tunable band gaps, prepared via a simple route of a direct metal surface elemental reaction, applied in the hole transport layer or buffer layer in thin-film solar cells to achieve higher efficiencies.

DMF‐Based Large‐Grain Spanning Cu2ZnSn(Sx,Se1‐x)4 Device with a PCE of 11.76%

“…To predict the photovoltaic performance of devices assembled with large-grain spanning absorbers, a transient surface photovoltage (TSPV) test was conducted on CZTSSe films. [33][34][35][36] TSPV test configuration is illustrated in Figure 5a. A 355 nm pulse laser with a pulse width of 4 ns was first processed by a reflector and then utilized for exciting the CZTSSe films in a shielding box.…”

Hyperactive Selenium Source Yields Kesterite Solar Cells with 12.86% Efficiency

“…This significant increase in T r suggests a significant inhibition of nonradiative recombination. [44][45][46][47] In addition, the band tailing was calculated by determining the energy difference between the derivative of EQE (dEQE/d𝜆) and the peak value of PL (E g − E PL ), where E PL represents the PL emission peak energy. The difference is 6 meV of the control sample and 2 meV of the Na 2 (Se 2 S)−7.5 sample, indicating less band tailing in the Na 2 (Se 2 S)−7.5 sample.…”

One-Step Gas–Solid-Phase Diffusion-Induced Elemental Reaction for Bandgap-Tunable CuaAgm1Bim2In/CuI Thin Film Solar Cells

“…As a result, a smaller fraction of silver bismuth and a larger fraction of bismuth octahedra would be beneficial to reduce the bandgap. The fabrication of films based on metal elemental surface reaction is a kind of redox reaction with elemental material sputtered film as raw material, which is beneficial to tune the element ratio and improve the quality of film formation [17,[26][27][28].…”