New method to extract the model parameters of solar cells from the explicit analytic solutions of their illuminated I–V characteristics

In this paper, a technique based on genetic algorithms is proposed for improving the accuracy of solar cell parameters extracted using conventional techniques. The approach is based on formulating the parameter extraction as a search and optimization problem. Current–voltage data used were generated by simulating a two-diode solar cell model of specified parameters. The genetic algorithm search range that simulates the error in the extracted parameters was varied from ± 5t o±100% of the specified parameter values. Results obtained show that for a simulated error of ±5% in the solar cell model values, the deviation of the extracted parameters varied from 0.1 to 1% of the specified values. Even with a simulated error of as high as ±100%, the resulting deviation only varied from 2 to 36%. The performance of this technique is also shown to surpass the quasi-Newton method, a calculus-based search and optimization algorithm.

https://iopscience.iop.org/article/10.1088/0957-0233/12/11/322/pdf

Solar cell parameter extraction using genetic algorithms

Schottky-barrier diodes (SBD's) fabricated in CMOS without process modification are shown to be suitable for active THz imaging applications Using a compact passive-pixel array architecture, a fully-integrated 280-GHz 4 × 4 imager is demonstrated At 1-MHz input modulation frequency, the measured peak responsivity is 51 kV/W with ±20% variation among the pixels The measured minimum NEP is 29 pW/Hz1/2 Additionally, an 860-GHz SBD detector is implemented by reducing the number of unit cells in the diode, and by exploiting the efficiency improvement of patch antenna with frequency The measured NEP is 42 pW/Hz1/2 at 1-MHz modulation frequency This is competitive to the best reported performance of MOSFET-based pixel measured without attaching an external silicon lens (66 pW/Hz1/2 at 1 THz and 40 pW/Hz1/2 at 650 GHz) Given that incorporating the 280-GHz detector into an array increased the NEP by ~ 20%, the 860-GHz imager array should also have the similar NEP as that for an individual detector The circuits were utilized in a setup that requires neither mirrors nor lenses to form THz images These suggest that an affordable and portable fully-integrated CMOS THz imager is possible

/pdf/active-terahertz-imaging-using-schottky-diodes-in-cmos-array-1lipxoxjoj.pdf

Active Terahertz Imaging Using Schottky Diodes in CMOS: Array and 860-GHz Pixel

Low-frequency noise study in electron devices: review and update

A simple method for extracting the parameters of the PV cell single-diode model

Simple, on-site parameter extraction methods are proposed; the ideality factor, series resistance, leakage resistance and saturation current are determined from the current-voltage characteristics of a Schottky barrier diode.

Simple parameter extraction method for non-ideal Schottky barrier diodes

An explanation of low frequency 1/f noise in nonideal Schottky barrier diodes is presented where the current fluctuation is attributed to the random walk of electrons at the metal-semiconductor interface via modulation of the barrier height. The experimental results on TiN/n-Si Schottky diodes have been successfully analysed to give useful information on the interface states.

Flicker noise by random walk of electrons at the interface in nonideal Schottky diodes

Applying a thermal activation model, we show that the power index γ of low frequency noise(1/ f γ ) in semiconductor structures can often be directly related to the ratio of thermal energy and a characteristic energy of the trap distribution, when there is a significant band tail or band bending. Some examples are discussed.

On 1/fγ noise in semiconductor devices

The non-homogeneous electrical parameters of carrier transport in silicon on sapphire (SOS) films are investigated through galvanomagnetic experiments using “MOS-Hall” thin (0.65 μm) SOS devices with low n-type dopings (n0 ⋍ 1015 to 1016 cm−3). Capacitance-voltage (C-V), Hall and magnetoresistance measurements are performed on the gate-controlled depleted or “active” layers of the film. Experimental results and theoretical calculations show that longitudinal magnetoresistance (LMR) measurements yield the accurate determination of anisotropy and carrier drift mobility. On the contrary, it is underlined that the (previous) characterization methods, exclusively based on C-V or Hall experiments could produce inconsistent and misleading results in SOS.

This is partly due to the fact that the usual 6 valley conduction band model used for bulk silicon is no longer valid in thin SOS films, for which the high stress at Si-sapphire interface requires the adoption of a 4 valley model throughout the film; this implies a high anisotropy for carrier mobility and explains why, in SOS films, the Hall mobility is 40% lower than the drift mobility, and the LMR is higher than the transverse magnetoresistance. C-V, Hall and LMR measurements then give fully consistent results allowing one to describe the variation of the carrier scattering mechanisms across the film and to determine the exact profiles for carrier mobilities and concentration as well as for the anisotropy coefficient.

J.I. Lee

Papers

Simple parameter extraction method for non-ideal Schottky barrier diodes

Flicker noise by random walk of electrons at the interface in nonideal Schottky diodes

On 1/fγ noise in semiconductor devices

Non-homogeneous electrical transport through silicon-on-sapphire thin films: Evidence of the internal stress influence

Low frequency noise measurements on TiN/n-Si Schottky diodes