Approaching 23% with large‐area monoPoly cells using screen‐printed and fired rear passivating contacts fabricated by inline PECVD

Abstract

We present n‐type bifacial solar cells with a rear interfacial SiOx/n+:poly‐Si passivating contact (‘monoPoly’ cells) where the interfacial oxide and n+:poly‐Si layers are fabricated using an industrial inline plasma‐enhanced chemical vapor deposition (PECVD) tool. We demonstrate outstanding passivation quality with dark saturation current density (J0) values of approximately 3 fA/cm2 and implied open‐circuit voltage (iVoc) of 730 mV at 1‐sun conditions after firing in an industrial belt furnace. Using a simple solar cell process flow that can be easily adapted for mass production, a peak cell efficiency of 22.8% with a cell open circuit voltage (Voc) of 696 mV is achieved on large‐area, screen‐printed, Czochralski‐silicon (Cz‐Si) solar cells using commercial fire‐through metal pastes.

Highly passivating and blister-free hole selective poly-silicon based contact for large area crystalline silicon solar cells

“…A promising way to passivate contacts while ensuring high-temperature stability is to use a highly-doped polycrystalline silicon (poly-Si) layer on top of a thin silicon oxide (SiOx) layer. The SiOx layer growth (thermal or chemical) is followed by the deposition of a-Si or poly-Si layers either by Low-Pressure Chemical Vapor Deposition (LPCVD) [5][6][7], or by Plasma-Enhanced CVD (PECVD) [8][9][10][11][12][13]. Recently, the fabrication of poly-Si layers using Physical Vapor Deposition (PVD) was also demonstrated [14].…”

“…Doping of the poly-Si layer can be performed in-situ by addition of a dopantrich precursor gas (e.g. B2H6 or PH3) [8,[11][12][13] or ex-situ (e.g. by diffusion [5,7] or ion implantation [15,16]).…”

“…Poly-Si/SiOx passivating structures demonstrated promising performances when integrated in solar cell devices with conversion efficiencies ≥ 25.8% obtained on small area devices (~2×2 cm 2 ) [18,19]. Conversion efficiencies ≥ 21.3% were also achieved on a large area device (~156×156 mm 2 ) with screen-printed metallization [7,13]. Despite the promising performances, these are some remaining challenges:…”

Different Conventional and Soft Computing MPPT Techniques for Solar PV Systems with High Step-Up Boost Converters: A Comprehensive Analysis

“…where I01-i, I01-j, and I02-j are the reverse saturation currents of single-diode model PV panel and doublediode circuit PV panel. From Equation (6), it can be seen that when the number of PV panel seriesconnected cells are increased and its equivalent voltage of PV increases [58,64]. From the single-diode circuit PV cell, the output current (I i ) is derived as,…”

“…There are three types of PV cell technologies, i.e., mono, poly, and thin film [6]. The mono and polycrystalline PV cells are designed using a microelectronic manufacturing technique and their efficiencies, as per REC solar energy reviews, are 21.7% [7] and 17.8% [8], respectively.…”