Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2409.20066

External quantum efficiency above 100% in photovoltaic cells due to the technique raising efficiencies for all kinds of solar cells

Jianming Li
View original source ↗Read source document ↗Export metadata ↓

Abstract

A V-shaped module (VSM) photovoltaic technique, which breaks traditional concepts, has been proven by European and American scientists to enable power-conversion-efficiency to increase by 50% for thin-film solar cells. Furthermore, the VSM technique raises power-conversion-efficiency for all kinds of solar cells (J. Environ. Sci. Eng. A 12, 214 (2023). https://doi.org/10.17265/2162-5298/2023.06.002). Mysterious dark energy is thought to result in the surprising VSM effect. The VSM approach opens up new avenues to study photovoltaic physics. In this study, the external quantum efficiency (EQE) of commercial polycrystalline silicon solar cells in the VSM was investigated, which exhibits a surprising phenomenon of EQE above 100%. In theory, non-infrared light incident into a solar cell can cause infrared emission. The VSM could trap the emitted infrared photons and lead to extra photoexcited carriers. The easy-to-reproduce VSM effect is thus explainable. The energy of emitted infrared photons is considered as the so-called dark energy. This study provides new clues and evidences to unravel the mystery of the surprising VSM effect. The VSM technique could also be used to develop photodetectors for infrared and ultraviolet light respectively.

Explore related subjects

physics.app-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jianming Li. 2026-07-07. External quantum efficiency above 100% in photovoltaic cells due to the technique raising efficiencies for all kinds of solar cells. https://arxiv.org/abs/2409.20066

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Janus Dipoles: Fundamentals, Realizations, and Emerging Applications

The Janus dipole - featuring orthogonally oriented electric and magnetic dipoles with a 90-degree phase difference - has emerged as a powerful paradigm for wave manipulation. Unlike traditional Huygens dipoles used for directional control, this unique configuration exhibits strongly asymmetric, face-selective near-field behavior while maintaining a quasi-isotropic far-field radiation pattern. These remarkable properties make the Janus dipole an essential platform for directional wave shaping, with wide-ranging applications in on-chip photonics, quantum interactions, and wireless power transfer. This review systematically traces the rapid development of the Janus dipole from its foundational theoretical inception to its diverse implementation platforms across optical, microwave, and acoustic frequencies. In this paper, we explore the governing principles, classify realization strategies into passive Janus dipoles, active Janus dipoles, and advanced near-field coupling control, and highlight emerging frontiers. By bridging foundational electrodynamics with advanced device engineering, this paper serves as an essential reference and roadmap for researchers designing next-generation, highly integrated, and compact wave-manipulation systems.

physics.app-ph↗
arXiv2026

Evaluation of effective wave velocities in polycrystalline materials using the ultrasonic reflection matrix

In-depth characterization of heterogeneous materials has long been a challenge in non-destructive testing. Here, a method is proposed to determine the elastic constants of metallic polycrystalline materials using back-scattered ultrasound. The waves scattered by the microstructure are analyzed to image the effective bulk velocities. To this end, a reflection matrix is acquired with an array of transducers. The projection of this matrix onto a focused basis is used to estimate an average point spread function. Optimizing this function with respect to the propagation model leads to an estimation of the longitudinal velocity. Additional treatments are developed to adapt the method to map the shear wave velocity. The local Poisson's ratio is then deduced from the ratio between those two velocities. Young's modulus and shear modulus can also be obtained assuming known densities. This matrix approach is experimentally validated on different polycrystalline materials. A sample displaying heterogeneous mechanical properties is then simulated to assess the accuracy and the resolution of the method. Its strengths and limitations are discussed, demonstrating its potential for quantitative non-destructive material characterization.

physics.app-ph↗
arXiv2026

Pendellösung length-scale neutron and X-ray interferometry

Neutron and X-ray perfect-crystal interferometers (PCIs) are powerful platforms for studies of fundamental physics and phase-contrast imaging. Further enhancing several PCI capabilities requires reducing crystal blade thickness to the micron scale, which minimizes dynamical-diffraction image blur, permits operation in the pendellösung regime where blade thickness controls beam splitting, and reduces absorption for simultaneous neutron and X-ray operation. However, fabricating multiple crystal blades with identical micrometer-scale thicknesses over centimeter-scale areas remains a major challenge. Here, using a non-etching sub-micron fabrication technique, we demonstrate silicon triple-Laue interferometers with equal-blade-thicknesses of 110 $μ$m and 350 $μ$m, operated with both neutrons and X-rays. These devices are the thinnest PCIs realized to date, enabling a factor-of-six reduction in dynamical-diffraction beam spreading for improved phase-contrast imaging, while reaching the single pendellösung length regime in which crystal thickness provides an experimentally accessible control parameter for engineered quantum-optical beam splitting of plane-wave inputs. These results motivate multi-blade PCI designs utilizing identical half-pendellösung crystal lamellae that are proposed for neutron spin--orbit and electric dipole moment measurements.

physics.app-ph↗