The reduction of the trap density at the SiC/SiO2 interface of a SiC MOSFET is still an open issue for the next generations development. Since TCAD simulations are one of the most powerful tools adopted in the field of power semiconductor devices, in this work we define the guidelines for the calibration of the TCAD model from the point of view of the interface traps modeling. We have carried out a qualitative analysis of the effect of the SiC/SiO2 interface traps properties on the C-V curve by means of TCAD simulations, to support the interpretation of the experimental C-V curves of a SiC MOSFET. A new approach for the simulation of the C-V curves of a SiC MOSFET is proposed as well. The aim of the paper is the analysis of the effect of the SiC/SiO2 interface traps on the C-V curve by means of TCAD simulations.

The aim of this work is to investigate the degradation of perovskite solar cells (PSCs) by means of impedance spectroscopy, a highly sensitive characterization technique used to establish the electrical response of a device in a nondestructive manner. In this paper, PSCs with two different electron transport layers (ETLs) are studied: PSCs with undoped SnO₂ as an ETL are compared to PSCs with an ETL composed of graphene-doped SnO₂ (G-SnO₂). Experimental data were collected immediately after fabrication and after one week, monitoring both impedance spectroscopy and dark current-voltage (I-V) curves. It was observed that, in the case of the undoped PSCs, the degradation of the solar cells affected both the AC behavior of the devices, modifying the associated Nyquist plots, and the DC behavior, observable from the dark I-V measurements. Conversely, the solar cells with G-SnO₂ showed no variation. Considering the Nyquist plots, a quantitative analysis was performed by comparing the parameters of a proper equivalent circuit model. The results were coherent with those achieved in the DC analysis, thus proving that the analysis of impedance spectra, supported with dark I-V curves, allows one to gain a deeper knowledge of the degradation phenomena of perovskite solar cells. This study opens the door for further improvement of these devices through a better understanding of their electrical behavior.

Cu₂ZnSnS₄ (CZTS) is a promising absorber material to produce thin film solar cells thanks to its high absorption coefficient, low cost and low toxicity. CdS is commonly used as a buffer layer for CZTS solar cells but, beyond its toxicity, it has a nonoptimal band alignment with CZTS. Zn_xSn_1−xO (ZTO), based on earth-abundant and nontoxic elements and with a large and tunable band gap, is a suitable alternative buffer layer. In this paper, the atomic layer deposition (ALD) of ZTO was employed by testing different compositions and thicknesses. ALD not only leads to very compact and homogenous ZTO layers (enabling tuning the stoichiometry of the ZTO so prepared) but also makes the i-ZnO layer (usually sandwiched between the buffer layer and the transparent contact) redundant and detrimental. Through SCAPS simulation and impedance measurements, the ZnSnO/AZO interface impact on the Cd-free kesterite solar cells’ performances has been investigated, highlighting its leading role in achieving an effective charge extraction and the detrimental effect of the i-ZnO layer. With this approach, a solar cell based on an architecture simpler and more eco-friendly than the conventional one has been produced with comparable efficiencies.

In this work, front contacts for graphene-based solar cells are made by means of colloidal graphite instead of gold. The performance is characterized by exploiting impedance spectroscopy and is compared to the standard gold contact technology. Impedance data are analysed through equivalent circuit representation in terms of lumped parameters, suitable to describe the complex impedance in the frequency range considered in the experiments. Using this approach, capacitance–voltage of the considered graphene–silicon solar cell is found and the barrier height forming at the graphene–silicon interface is extracted.

The behavior of a photovoltaic (PV) generator under specific irradiance and temperature conditions is mainly described by its current–voltage (I-V) characteristic. Therefore, the I-V curve tracing has to be considered the most accurate and effective diagnostic tool for the proper identification of PV panels’ failures. In this article, an innovative I-V curve tracer for individual PV panels is presented. It ensures the following advantages. 1) An optimized I-V curve measurement due to an innovative tracing algorithm. 2) In-situ characterization during normal operation owing to a proper disconnection circuit. 3) Full portability thanks to a Li-ion battery power supply and a Bluetooth communication. The proposed tool has been designed and realized. The resulting prototype has been used to measure the I-V curve of a PV panel both in uniform and partial shading conditions.