Table 3.

Calculated X/MXene vdW properties, including work function of X, MXenes, X/MXene structures, lattice mismatch, binding energy (E _b), electronic/hole barrier (eV), tunneling barrier height (φ _T). In the work function column, E _c, E _v, and E _f stand for conduction band minimum, valance band maximum, fermi level, respectively. In the binding energy column, there is a mark “*” and “**” in the binding energy to represent the unit as “J m⁻²” and “eV Å⁻².” “X” represents material forming the vdW heterostructure with MXenes. “Oh” represents an Ohmic contact, “LS” represents a low Schottky barrier contact

Contact material	Work function	Contact	Work function [eV]	Mismatch [%]	Binding energy E b [meV]	Heterojunction work function	Electronic barrier [eV]		Hole barrier [eV]		Tunneling barrier (φ T)		Ref.
							Vertical direction (${\phi }_{\mathrm{V}}^{\mathrm{e}}$)	Lateral direction (${\phi }_{\mathrm{L}}^{\mathrm{e}}$)	Vertical direction (${\phi }_{\mathrm{V}}^{\mathrm{h}}$)	Lateral direction (${\phi }_{\mathrm{L}}^{\mathrm{h}}$)
ML WSe2	–	NbSe2	–	–	–	–	–	–	0	0	0		[20]
		Ti2C	–	–	–	–	0	0.43	0	–	0
		Ti2C(OH)2	–	–	–	–	0	0	–	–	0
		Mo2CF2	–	–	–	–	–	–	0	0	0
		Mo2CO2	–	–	–	–	–	–	0	960	0
2L WSe2		Ti2C	–	2.16	−120	–	0	0.40	0	0.68	0		[26]
		Ti2C(OH)2	–	2.18	−330	–	−0.04	−0.03	1.30	1.25	0
		Mo2CF2	–	2.37	−120	–	1.25	1.25	0.02	0.02	0
MoS2	E c: 5.97	Nb2C(OH)2	2.14	1	–	–	−0.03		1.69		–		[26]
		F	4.36	–	–	–	0.49		1.14		–
		O	5.71	–	–	–	1.44		0.26		–
C2N	E c: 4.42 E v: 6.08	Hf2C(OH)2	2.26	1.65	–	–	−0.21		1.65		–		[204]
		Nb2CF2	4.47	0.77	–	–	0.06		1.60		–
		MO2NO2	5.82	0.61	–	–	1.34		0.33		–
ReS2	4.58	Ti3C2	4.40	4.04	780	4.32	0	−0.15	0		1.20	0.24	[205]
	4.40	Hf3C2	4.58	0.13	740	4.53	0	−0.07	0		1.22	0.23
InSe	E c: 4.37 E v: 6.51	TaSe2	5.65	−1.55	0.29*	5.55	0.86 (1L)		0.65 (2L)		2.20		[184]
		VSe2	5.75	−5.52	0.31*	5.64	0.57		0.46		2.38
		NbSe2	5.82	−0.98	0.30*	5.74	0.58		0.40		2.15
		TaS2	6.23	5.24	0.30*	6.13	0.28		0.10		2.40
		VS2	6.30	−3.03	0.33*	6.29	0.39		–		2.16
		NbS2	6.44	−4.67	0.33*	6.29	0.22		0.09		2.41
MoS2	5.95	V2CO2	6.70	<1	0.018**	–	–		0.052		–		[187]
		Cr2CO2	7.65	<1	0.025**	–	–		0.005		–
		Mo2CO2	7.50	<1	0.024**	–	–		−0.185		–
		V4C3O2	6.65	<1	0.015**	–	–		0.027		–
		Cr2NO2	7.00	<1	0.019**	–	–		−0.102		–
		V2NO2	6.30	<1	0.016**	–	–		0.022		–
MoS2	–	Ta2C	–	–	–	–	S		–		–		[27]
		Ta2CF2	–	–	–	–	Oh		–		–
		Ta2C(OH)2	–	–	–	–	Oh		–		–
Black Phosphorus	E c: 4.12 E f: 4.75 E v: 5.03	Zr2CO2	5.07	0.27	−160	–	–	–	–		–		[28]
		Zr2CF2	3.39	2.04	−140	4.30	Oh	LS	–		3.69
		Zr2CO2H2	2.10	0.27	−380	4.26	Oh	LS	–		2.02
		Zr3C2O2	5.13	0.26	−170	5.25	Oh	Oh	–		4.57
		Zr3C2F2	3.65	0.37	−140	5.02	Oh	LS	–		4.09
		Zr3C2O2H2	2.04	0.37	−350	4.18	Oh	LS	–		2.30
Blue P	–	Ti3C2O2	–	4.30	−235.1	–	1.30		0.00		–		[29]
		Ti3C2(OH)2	–	2.70	−560.2	–	−0.17		1.70		–
		Ti3C2F2	–	3.11	−254.2	–	1.34		0.68		–
		Zr3C2O2	–	0.78	−81.5	–	1.45		−0.37		–
		Zr3C2(OH)2	–	1.40	−630.5	–	0.00		1.65		–
		Zr3C2F2	–	2.81	−476.9	–	−0.24		1.39		–
		Hf3C2O2	–	0.02	−435.2	–	1.47		0.00		–
		Hf3C2(OH)2	–	0.61	−431.8	–	−0.06		1.87		–
		Hf3C2F2	–	0.52	254.2	–	0.12		1.75		–
MoS2	–	Ti3C2O2	–	3.58	−185.6	–	1.70		−0.04		–		[240]
		Ti3C2(OH)2	–	1.99	−265.9	–	0.00		1.40		–
		Ti3C2F2	–	2.39	−190.8	–	0.82		0.86		–
		Zr3C2O2	–	1.45	−432.3	–	0.62		−0.23		–
		Zr3C2(OH)2	–	2.06	−442.7	–	−0.25		0.75		–
		Zr3C2F2	–	3.46	−328.6	–	−0.05		0.59		–
		Hf3C2O2	–	0.66	−308.6	–	0.95		0.00		–
		Hf3C2(OH)2	–	1.28	−434.8	–	−0.02		1.12		–
		Hf3C2F2	–	1.19	−298.7	–	0.08		1.09		–
Graphene	–	Cr2C	4.54	3.34	334	4.26	0	0.04	0		0.10	–	[241]
		Ta2C	4.94	3.34	334	4.63	0	0.01	0		0.02	–
		V2C	4.80	3.34	334	4.46	0	0.00	0		0.20	–
Tl2O	E c: 3.61 E f: 4.59 E c: 4.61	Ti2C	4.43	1.51	129	3.98	–	0.36	–		0.65	0	[203]
		Ti2C(OH)2	1.66	0.56	430	1.10	–	0.00	–		1.02	0
		Ti2CF2	4.92	1.10	240	4.81	–	0.98	–		0.00	0
carbon sulfide (CS)	–	Ti2CO2	–	–	−1234	–	0.58		0.69		–		[242]
		Zr2CO2	–	–	−39	–	0.50		2.59		–
		Hf2CO2	–	–	−357	–	0.21		3.69		–