Photovoltaics

The challenges of developing stable perovskite material and fabrication processes for commercial use require the use of several spectroscopic techniques such as Raman, Photoluminescence (PL), and Time-resolved photoluminescence (TRPL), etc. to characterize and optimize the material design and fabrication processes.

The Fluorolog-QM fluorescence spectrometer with an integrating sphere option is an excellent choice for PLQY measurements in NIR. The K-Sphere is very convenient and easy to use, as it couples directly to the sample compartment optics and allows a use of external light sources, such as DPSS lasers, which can be attached to the front of the sample compartment. The sphere has holders for cuvettes, slides and powders that can be easily interchanged. The results demonstrate very good reproducibility and precision for NIR PLQY measurements spanning almost two orders of magnitude. Based on multiple measurements, the demonstrated PLQY standard deviations range from 1.3% for high QY value (77%) to 6.4% for the QY below 1%.

The new Fluorolog-QM spectrofluorometers, due to their modularity and advanced software and a universal interface, are an ideal choice for studying multiple aspects of upconversion. This technical note illustrates the use of Fluorolog-QM-75-21 for spectral and time-resolved characterization of these materials.

Graphene, a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice, exhibits remarkable electrical, thermal, and mechanical properties, making it a subject of extensive research in various scientific fields.

Time-resolved photoluminescence (TRPL) spectroscopy is an important tool which can be used to characterize optical materials such as LEDs and photovoltaic (PV) materials.

Van der Waals heterostructures, with their unique properties arising from the weak interlayer coupling and strong in-plane bonding, offer exciting opportunities for the design of novel materials with tailored electronic, optical, and mechanical properties.

With their ~20 % efficiency, hybrid perovskite solar cells are the new promising candidate for next generation photovoltaics. Thanks to the wide HORIBA Scientific portfolio, different techniques can be used to gain in depth knowledge on the optoelectronic properties and mechanisms of this class of materials. In this application note we decided to use spectroscopic ellipsometry, steady-state and time-resolved fluorescence and Glow Discharge Optical Emission Spectroscopy to investigate the properties of CH3NH3PbI3 thin films deposited on a spin-coated PEDOT:PSS. The impact of the exposure to air was addressed.

Hybrid organic-inorganic perovskite materials have emerged over the past five years as promising absorber layers for new high-efficiency and low-cost solar cells that combine the advantages of organic and inorganic semiconductors. The increasing interest in this technology is pushing research laboratories to find the optimal techniques for the accurate characterization of opto-electronic properties of these materials.

Spectroscopic Ellipsometry is an efficient and non-destructive method for extracting optical constants of materials in the UV-VIS-NIR wavelength ranges. The optical constants (n,k) of a material are among the most important sets of optical data and are specific to the material being studied. During this webinar, you will learn how to define a strategy to perform quantitative Spectroscopic Ellipsometry on CIGS semiconducting thin films. CIGS is among the most efficient absorbers for photovoltaic solar conversion. Deployed as thin or ultra thin films, CIGS optical characterization is as important in its preparation stage as in the modeling of cell stacks. However the determination of CIGS optical constants is a very complex challenge, particularly for SE when it is used as a unique and direct experimental method.

Photoluminescence spectroscopy (PL) is a powerful optical method used for characterizing materials. PL can be used to find impurities and defects in silicon and group III-V element semiconductors, and to determine semiconductor band-gaps.

Temperature-dependent photoluminescence (PL) spectroscopy is a powerful optical method for characterizing materials. PL can be used to identify defects and impurities in Si and III-V semiconductors, as well as determine semiconductor bandgaps. At room temperature, PL emission is usually broad—up to 100 nm in width.

As a result of rapid development in semiconductor manufacturing, many types of optoelectronic devices such as laser diodes, LEDs, and high-electron-mobility transistors (HEMTs) are now fabricated by epitaxial-growth methods.

Gallium Nitride (GaN) is one of a generation of promising light-emitting materials. Its direct energy band gap of ~3.4 eV at room temperature make it particularly suitable for emission in the blue, and near UV spectral ranges. The material often exhibits high temperature stability and low electrical leakage, and hence GaN is generally a good candidate for fabricating high-temperature and high-power devices.

Photoluminescence is the optical emission obtained by photon excitation (usually a laser) and is commonly observed with III-V semiconductor materials. This type of analysis allows non-destructive characterization of semiconductors (material composition, qualitative investigations, etc.

III-V semiconductors are important to the fabrication of active photonic devices such as light sources and detectors. Successful fabrication of such devices relies on the high quality of the underlying materials and precise deposition of intended geometries on a wafer substrate.

Monolithic integration of optical components on CMOS platforms is ongoing in the optical communications industry. CMOS offers a mature and robust platform, and therefore is logical for building optical-interconnect modules.

For thirty years there has been a research focused onto carbonization of 3D structures especially to be employed in electronic applications. These structures are prepared with the help of lithography and pyrolyzed afterwards. For making features below 100 nm, a bottom-up approach using lipids nanotubes is attempted.

GaN and related alloys are important materials used to build short-wavelength light sources (lasers and LEDs). Room- and low-temperature photoluminescence (PL) are used to characterize these materials as well as device performance.

Hybrid perovskite photovoltaics (PV) show promise because of their good efficiencies, which can be around 20%. Along with their PV characteristics, perovskite materials exhibit a high degree of radiative recombination.

Internal Quantum Efficiency (IQE) and External Quantum Efficiency (EQE) measurements are indicators of the effectiveness of a photosensitive device such as those used in telecommunications and solar cells. EQE is the ratio of the charges generated to the total amount of photons incident on the surface; a larger EQE indicates a more efficient device.

The phenomenon of upconversion is an optical process that takes in lower energy (longer wavelength) photons and emits higher energy (shorter wavelength) photons.

Glasses are essential materials with a multitude of uses and many forms. In the area of optoelectronics there is an interest to modify the glass composition to favor the incorporation of lanthanide elements.

This technical note serves as a guideline to selecting the best solid state detector with the Fluorolog-QM modular research spectrofluorometer for a given series of photoluminescence experiments.