Supplementary information
Probing the Defects in Nitrogen Doped Cu2O
Junqiang Li, Zengxia Mei, Lishu Liu, Huili Liang, Alexander Azarov, Andrej Kuznetsov,
Yaoping Liu, Ailin Ji, Qingbo Meng, and Xiaolong Du
Van der Pauw configuration was used for Hall measurements. The results were confirmed
with a home-made Hall system. The Hall coefficients were extracted from the tracing curve of
transverse voltage recorded with alternating magnet field and constant current (See Figure S1
and reference 1 in supporting information).
The temperature dependent hole concentration of annealed Cu2O:N sample is shown in Figure
S2. The acceptor level is calculated to be 121 meV by fitting the data with the equations (1)
and (2) presented in method section.
Figure S3 is the schematic of the formation of an aggregation of four Cu atoms accompanying
VO in Cu2O.
The Cu3N film were fabricated on Si substrate by reactive magnetron sputtering with Cu
target and nitrogen gas. For more details about the synthesis of Cu3N, please refer to reference
2 in supporting information. The Cu LMM Auger spectrum is shown in Figure S4. The
dominant peak is located at 916.8 eV.
Figure S5 shows Cu 2p spectra of the same sample as a function of the depth. Zero nm stands
for the original surface before Ar ion sputtering. As indicated in the figure, the original surface
of the sample contains some Cu2+ components evidenced by the fitting of Cu2p2/3 peak and
the characteristic satellite peak. The existence of CuO and Cu(OH)2 is due to the exposure of
the Cu2O surface to the atmosphere. After Ar ion sputtering, the Cu2+ component disappeared.
For the two depths, sputtering rates were varied by setting different acceleration voltage and
beam current, however the resulted spectra show no consequential changes, indicating that
exfoliation rate is fast enough that the damage effect is not significant and can be ignored.
References:
[1] Y. Guo, Y. P. Liu, J. Q. Li, S. L. Zhang, Z. X. Mei, X. L. Du, Chin. Phys. Lett. 2010, 27,
067203.
[2] A. L. Ji, N. P. Lu, L. Gao, W. B. Zhang, L. G. Liao, Z. X. Cao, J. Appl. Phys. 2013, 113,
043705.
Figure S1 The tracing curves of transverse voltage in Hall measurement for Cu2O:N samples
before and after anneal. The current is fixed at 10 μA and the applied magnet field varied with
time as indicated in the figure. The linear background in the curve of unannealed sample
originates from the persistent photoconductivity of Cu2O. The inset shows the electrode
configuration
Figure S2 Temperature-dependent hole density of 750℃ annealed Cu2O:N and the fitting
curve with equation (1) and (2).
.
Figure S3Schematic of the four Cu atoms’ aggregation when an oxygen atom is lost and Cu
dangling bonds form. The big balls represent for oxygen atoms while the small ones copper
atoms.
Figure S4 Cu LMM spectrum of Cu3N film.
Figure S5 Depth-dependent Cu2p spectra of Cu2O:N.