Nitrogen effect on negative fixed charges of Al<inf>2</inf>O<inf>3</inf> passivation film in crystalline Si solar cells

Abstract

We demonstrated the electrical evolution of the AlO, AlN, and AlON and the nitrogen (N) effect on negative fixed charges, which is responsible for the reduced positive charge traps of Al2O3 passivation films in crystalline Si solar cells. The AlO and AlN deposited by RF sputtering system were served as reference samples, and the AlON prepared by a nitrogen plasma exposure was served as controlled sample. The electrical properties of these samples were demonstrated through high-low (HL) capacitance-voltage (C-V) of metal-insulatorsemiconductor (MIS) and photo-induced current transient spectroscopy (PICTS) to investigate interface and bulk defect states in the insulating films. 1MHz C-V curves of AlO, AlN, and AlON films, in which flatband voltage shifts (VFB) are around -0.55, -2.8 and 3.6 V, respectively. It reveals that the positive shift takes place as compared to the others and negative fixed charges are dominant in the AlON film. It was observed that defect states were decreased in the AlON film, and especially the defect state of 0.42 eV approximately disappeared. From the HL

Composition and Properties Control Growth of High-Quality GaOxNy Film by One-Step Plasma-Enhanced Atomic Layer Deposition

“…Several studies have reported that silicon oxynitride (SiO x N y ) film presented better electrical properties than the silicon oxide in various aspects, for example, when it was used as a gate dielectric in a metal–insulator–semiconductor (MIS) structure. , Researchers also found that the amorphous zinc oxynitride (ZnO x N y ) was a promising semiconductor that presents both high device performance and stability. − Apart from that, aluminum oxynitride (AlO x N y ) is proven to possess distinct advantages over alumina oxide and nitride. It has been used in applications with high-k and photovoltaic fields due to its superior characteristics like lower leakage current, higher breakdown voltage, and outstanding passivation quality . Other oxynitrides (ZrO x N y , SnO x N y , TaO x N y ) also present optical, electrical, or electrochemical properties in different applications.…”

“…It has been used in applications with high-k 17 and photovoltaic fields 8 due to its superior characteristics like lower leakage current, 18 higher breakdown voltage, 19 and outstanding passivation quality. 20 Other oxynitrides (ZrO x N y , 21 SnO x N y , 22 TaO x N y 23 ) also present optical, electrical, or electrochemical properties in different applications.…”

Plasma nitridation of atomic layer deposition (ALD) Al2O3 by NH3 in plasma-enhanced chemical vapor deposition (PECVD) for silicon solar cell

“…The oxynitride in the interface of the sample nitrided at 400 W, in fact, was very noticeably increased. This phenomenon, which has been linked to the change of interfacial bonds resulting from the reduction of interfacial defects, can enhance surface passivation [9][10][11][12][13].…”

“…The structure of Al 2 O 3 /SiNx passivation experience plasma exposure on the Al 2 O 3 passivation layer in PECVD. Nitridation of films by nitrogen and ammonia plasma exposure has often been employed in the solar cell and semiconductor device field [9,10]. AlON films can form in a similar way at the Al 2 O 3 /SiNx interfacial layer.…”

“…AlON films can form in a similar way at the Al 2 O 3 /SiNx interfacial layer. Notably, it has been reported that AlON films have a higher density of negative fixed charge than do Al 2 O 3 films [9,10].…”