electrical engineering
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SIMS (Secondary Ion Mass Spectrometry) instrumentation is designed to analyze the surface composition of materials by detecting ions ejected from the surface. The system includes a primary ion source that fires a focused beam of ions (like gallium or cesium) onto the sample. This bombardment knocks atoms and molecules off the surface, some of which…
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Polycrystalline silicon, often called poly-si, is a special material used to build the tiny pathways inside computer chips. Its main job is to control the flow of electricity, and a key property it has is called resistance. Resistance is how much a material slows down or fights against the electric current. Think of it like trying…
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Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) is a powerful technique used to analyze the surface of materials by detecting the chemical composition of just the outermost layers. The technique allows for analysis of a chemical structure in 3D with nanoscale resolution. In this method, a sample is bombarded with a focused beam of primary ions.…
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The solar energy industry traces its roots to nineteenth century scientific discoveries, beginning with the photovoltaic effect identified by Edmond Becquerel in 1839 and early selenium based cells in the late 1800s. It did not become a modern commercial sector until Bell Labs created the first practical silicon solar cell in 1954, which initially found…
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Scanning Electron Microscopy, or SEM, is a way to take very close‑up pictures of tiny things by shooting a thin beam of electrons onto a sample and moving the beam back and forth like a scanner. When the electrons hit the surface, they knock out other electrons and sometimes cause the material to emit X‑rays;…
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Electron beam characterization involves using a focused beam of electrons to probe and analyze materials at very fine scales. Techniques such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM) rely on the interaction between electrons and the atoms in a sample to reveal details about surface morphology, internal structure, and even chemical composition.…
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The source‑series resistance (Rₛ) and drain‑series resistance (Rᴅ) are the parasitic resistances that appear in series with the source and drain terminals of a MOSFET. They arise from the silicon substrate, metallization layers, and package leads that connect the internal transistor to the external pins. When the device is turned on, the total on‑resistance (Rₒₙ)…
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Solar cells, often called photovoltaic cells, are semiconductor devices that convert light from the sun directly into electrical energy. They form the basic building block of solar panels and many other solar power systems. Basic idea A solar cell takes incoming light, absorbs part of that light inside a semiconductor, and turns the absorbed energy…
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Determining the threshold voltage of a MOSFET means figuring out how much gate voltage is needed before a strong conducting channel forms at the semiconductor surface. At low gate voltage the semiconductor surface is either slightly depleted or slightly accumulated and the device does not conduct much. As the gate voltage is increased the electric…
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MOSFETs, or Metal-Oxide-Semiconductor Field-Effect Transistors, are essential components in modern electronics, and understanding their operating characteristics is crucial for anyone interested in electronics. These devices function as switches or amplifiers, controlling the flow of electrical current. The key to their operation lies in the voltage applied to the gate terminal, which influences the conductivity between…
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Understanding oxide charge density in semiconductors is an important concept in electronics and materials science. Semiconductors are materials that have electrical properties between those of conductors and insulators. They are essential for making electronic devices like computers and smartphones. The oxide charge density refers to the amount of electric charge that is stored in the…
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The flatband capacitance (CFB) is defined as the total measured capacitance of a Metal-Oxide-Semiconductor (MOS) structure or a similar semiconductor device when the applied gate voltage is exactly equal to the flatband voltage VFB. This flatband voltage represents the specific potential needed to establish the flatband condition, where the energy bands within the semiconductor substrate…
