Diagnostics of thin-film silicon solar cells and solar panels/modules with variable intensity measurements (VIM)

Charge collection in amorphous silicon solar cells: Cell analysis and simulation of high-efficiency pin devices

“…The correlation between V coll and FF is discussed in [10,12]. Here, V coll determined from EQE measurements is compared to the electric field deformation resulting from the simple model, and to a more precise simulation of the deposited cells (see Section 3) by the ASA package.…”

“…Thanks to its independence from the collection model and other parameters such as parallel and series resistance, V coll is a good parameter for intrinsic charge collection that can provide additional information to e.g. quantum efficiency or fill factor [10]. In a more intuitive approach, V coll is the voltage that must be applied to the equivalent ohmic resistance R sc for a current J sc to flow.…”

Trigonal‐Bipyramidal and Square‐Pyramidal ChromiumManganese Chalcogenide Clusters, [E2CrMn2(CO)n]2− (E=S, Se, Te; n=9, 10): Synthesis, Electrochemistry, UV/Vis Absorption, and Computational Studies

“…According to 9, 10, $ R_{{\rm sc}{\rm,dark}} > 20\;{\rm k\Omega }\; {\rm \rm cm}^{2} $ is required for a‐Si:H/a‐Si:H tandem cells, without considering the patterning isolation of the monolithic module interconnection. Our study evaluates $ R_{{\rm sc}{\rm,dark}} $ by linear fitting of the dark $ I - V$ characteristics of each cell of the module, including the impact of the patterning process, within the voltage range $ - 0.1\;{\rm V} \le V_{\rm c} \le 0.1\;{\rm V}{.…”

Internal electric field and fill factor of amorphous silicon solar cells

“…From VIM, the fill factor FF and the collection voltage Vcoll were determined via the short-circuit resistance Rsc and the short-circuit current density Jsc as described in [2]. Figure 9 shows such a measurement from which Vcoll could be determined as coll sc sc…”

“…Whereas microcrystalline silicon solar cells are generally not seriously affected by collection problems up to i-layer thicknesses of about 5 µm [1], amorphous silicon (a-Si:H) solar cells have to be kept very thin (< 300 nm) to avoid any breakdown of E in the degraded state. The purpose of the present paper is threefold: (1) to propose a very simple model for the approximate calculation of different terms contributing to the field deformation ∆E(x) within the i-layer of a-Si:H solar cells; (2) to present simulation results for pin-type solar cells with i-layers of 100, 200, 300 and 400 nm thickness on flat substrates; (3) to compare these numerical results with measurements done on corresponding cells produced at IMT Neuchâtel. Thereby, the following techniques were used to gather experimental data: J(V), VIM (Variable Intensity Measurements) [2], and bifacial EQE (External Quantum Efficiency) measurements [3] varying both bias voltage Vbias and bias light intensity.…”