Journal Article

FZJ-2021-04735

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Function Analysis of the Phosphine Gas Flow for n-Type Nanocrystalline Silicon Oxide Layer in Silicon Heterojunction Solar Cells

Qiu, D.FZJ* ; Duan, W. (Corresponding author)FZJ* ; Lambertz, A.FZJ* ; Wu, Z. ; Bittkau, K.FZJ* ; Qiu, K. ; Yao, Z. ; Rau, U.FZJ* ; Ding, K.FZJ*

2021
ACS Publications Washington, DC

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/30308  doi:10.1021/acsaem.1c00654

Abstract: The energy conversion efficiency (η) of silicon heterojunction (SHJ) solar cells is limited by the current losses in the layer stack on the illuminated side. To reduce these losses, hydrogenated nanocrystalline silicon oxide (nc-SiOx:H) was implemented as a window layer in SHJ solar cells. However, the integration of nc-SiOx:H in devices without degradation of fill factor (FF) is still a challenge. To optimize the electron performance of devices, the optoelectronic properties and microstructure of nc-SiOx:H were characterized and analyzed systematically. It was found that the PH3 gas fraction (fPH3) plays a big role on the microstructure, oxygen content, and phosphorus (P) doping efficiency of the films. The highest conductivity, 2.84 × 10–1 S/cm, is obtained at a moderate fPH3 with an optical band gap of 2.26 eV. A ternary model was creatively used to show the variation in the composition of nc-SiOx:H as tuning fPH3. The growth of crystalline phase was accelerated by the P dopants when fPH3 is low, but further increasing fPH3 leads to excessive P inactive dopants, causing a phase transition from nanocrystalline silicon to amorphous silicon in nc-SiOx:H. In this work, the best solar cell with an nc-SiOx:H window layer achieves an FF of 81.4%, a short current density (Jsc) of 39.8 mA/cm2, an open-circuit voltage (Voc) of 731 mV, and an η of 23.7% at the moderate fPH3. A decrease in FF and Jsc is shown with higher fPH3, which is the consequence of the increased front contact resistivity and decreased optical band gap of nc-SiOx:H window layer.

---

Contributing Institute(s):

1. Photovoltaik (IEK-5)

Research Program(s):

1. 1213 - Cell Design and Development (POF4-121) (POF4-121)

Appears in the scientific report 2021

---

Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---