Electrical Transport — Unveiling high-mobility hot carriers in a two-dimensional conjugated coordination polymer

5 measurement groups · 23 results

Reported values remain attached to the sample, method, conditions, extraction quality and source location that produced them.

Four-terminal longitudinal conductivity

Electrical conductivity

large-area Cu3BHT film on fused silica · Thin Film

Commercial Physical Property Measurement System; AC lock-in method at 17.777 Hz using Stanford Research System 830 lock-in amplifier source meter; variable temperature 2-300 K.

Temperature: 2-300 K; room-temperature value reported in main text
Atmosphere: not stated
Geometry: four-terminal transport device
Context: pristine Cu3BHT film
Measurement source: 3 · Variable-temperature conductivity · Supplementary Fig. 9

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Room-temperature electrical conductivity of synthesized Cu3BHT filmMarked as a best value within this paper	~48 S cm-1	4800 S m-1	—	Text Approximate	2 · Synthesis and characterization · Supplementary Fig. 9
Variable-temperature conductivity trend	negative temperature coefficient of conductivity from 2 K to 300 K	—	—	Text Qualitative	13 · Supplementary Fig. 9 · Supplementary Fig. 9

Transient absorption microscopy (TAM)

Transient absorption spectroscopy

large-area Cu3BHT film on fused silica · Thin Film

Pump/probe from PH1-20 and TOPAS-Twins; Nikon 10x objective; galvo scanning of probe beam relative to pump; spatially resolved charge population; main data at Nabs = 0.7 x 10^15 cm^-2.

Temperature: room temperature
Atmosphere: not stated
Geometry: spatially resolved pump-probe microscopy of thin film
Context: pristine Cu3BHT film
Measurement source: 10 · Methods - TAM · Fig. 4e-g

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Ambipolar mobility from TAM band-edge diffusion	42 +/- 8 to 72 +/- 12 cm2 V-1 s-1	—	range; +/- 8 and +/- 12 cm2 V-1 s-1 endpoints	Text Range	7 · Spatiotemporal and energetic evolution · Supplementary Fig. 17
Band-edge diffusion rate at 2.21 eV after fast diffusion phase	2.4 +/- 0.8 cm2 s-1 at 2.21 eV	—	+/- 0.8 cm2 s-1	Text Exact Reported	24 · Supplementary Fig. 18 · Supplementary Fig. 18e
Band-edge diffusion rate at 2.59 eV after fast diffusion phase	3.9 +/- 0.8 cm2 s-1 at 2.59 eV	—	+/- 0.8 cm2 s-1	Text Exact Reported	24 · Supplementary Fig. 18 · Supplementary Fig. 18e
Band-edge carrier diffusion coefficient rangeMarked as a best value within this paper	1.1 +/- 0.2 to 1.9 +/- 0.3 cm2 s-1	—	range; +/- 0.2 and +/- 0.3 cm2 s-1 endpoints	Text Range	7 · Spatiotemporal and energetic evolution · Supplementary Fig. 17; Supplementary Table 6
Hot-carrier propagation lengthMarked as a best value within this paper	200 nm to 320 nm; Supplementary Table 5: ~300 nm	—	range	Text Range	7 · Spatiotemporal and energetic evolution · Supplementary Fig. 17; Supplementary Table 5
Hot-carrier diffusion coefficient at 1.77 eV excitation	677 +/- 59 cm2 s-1	—	+/- 59 cm2 s-1	Text Exact Reported	6 · Spatiotemporal and energetic evolution · Fig. 4g; Supplementary Table 6
Hot-carrier diffusion coefficient at 2.59 eV excitationMarked as a best value within this paper	1,224 +/- 94 cm2 s-1	—	+/- 94 cm2 s-1	Text Exact Reported	6 · Spatiotemporal and energetic evolution · Fig. 4g; Supplementary Table 6
Hot-carrier diffusion coefficient range from Supplementary Table 6	677 +/- 59-1224 +/- 94 cm2 s-1	—	range with endpoint uncertainties	SI Table Range	35 · Supplementary Table 6 · Supplementary Table 6

Time-resolved terahertz spectroscopy (TRTS), fluence-dependent dynamics

Terahertz spectroscopy

large-area Cu3BHT film on fused silica · Thin Film

~50 fs pump pulses; 1.55 eV excitation; Nabs 2.7-19.1 x 10^14 cm^-2; THz probe ~1 ps; dry N2-purged transmission mode at room temperature.

Temperature: room temperature
Atmosphere: dry N2-purged environment
Geometry: contact-free THz transmission through thin film
Context: pristine Cu3BHT film
Measurement source: 4 · Highly mobile hot carriers and hot phonon bottleneck · Fig. 2a,e,f

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Critical photon energy from Delta sigma peak/offset extrapolation	~560 +/- 50 meV	0.56 eV	+/- 50 meV	Text Approximate	4 · Highly mobile hot carriers · Fig. 2d
Hot-carrier cooling time above 10^15 cm-2	~750 fs	0.75 ps	—	Text Approximate	4 · Highly mobile hot carriers · Fig. 2e
Hot-carrier cooling time below 10^15 cm-2	~500 fs	0.5 ps	—	Text Approximate	4 · Highly mobile hot carriers · Fig. 2e
Band-edge carrier recombination time t2	t2 ~= 1.2 ns	1200 ps	—	Text Approximate	4 · Highly mobile hot carriers · Fig. 2f
Corresponding three-dimensional carrier density range	1.4-9.6 x 10^20 cm-3	—	range	Caption Range	4 · Fig. 2 caption · Fig. 2a
Absorbed photon fluence range	2.7-19.1 x 10^14 cm-2	—	range	Caption Range	4 · Fig. 2 caption · Fig. 2a

Frequency-resolved complex TRTS with Drude/Drude-Smith fits

Terahertz spectroscopy

large-area Cu3BHT film on fused silica · Thin Film

Complex THz photoconductivity at 0.5 ps and 5 ps after Delta sigma peak under 1.55 eV photoexcitation, Nabs = 0.6 x 10^15 cm^-2.

Temperature: room temperature
Atmosphere: dry N2-purged environment
Geometry: contact-free THz transmission through thin film
Context: pristine Cu3BHT film
Measurement source: 5 · Crossover from non-equilibrium to quasi-equilibrium regime · Fig. 3a,b

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Intrinsic diffusion length of band-edge carriersMarked as a best value within this paper	~1,100 +/- 300 nm	1.1 um	+/- 300 nm	Text Approximate	5 · Crossover from non-equilibrium to quasi-equilibrium regime · Supplementary Table 5
Band-edge carrier mobility from TRTS Drude fitMarked as a best value within this paper	405 +/- 30 cm2 V-1 s-1	—	+/- 30 cm2 V-1 s-1	Text Exact Reported	5 · Crossover from non-equilibrium to quasi-equilibrium regime · Fig. 3b; Supplementary Table 5
Quasi-equilibrium Drude scattering time tau	~41 +/- 3 fs	—	+/- 3 fs	Text Approximate	5 · Crossover from non-equilibrium to quasi-equilibrium regime · Fig. 3b
Hot-carrier mobility inferred from photoconductivity ratioMarked as a best value within this paper	approximately 2,000 cm2 V-1 s-1; Supplementary Table 5: up to 2,000	—	—	Text Approximate	5 · Crossover from non-equilibrium to quasi-equilibrium regime · Fig. 3; Supplementary Table 5

Temperature-dependent TRTS

Terahertz spectroscopy

large-area Cu3BHT film on fused silica · Thin Film

Cu3BHT film in cryostat under vacuum below 1 x 10^-4 mbar; 1.55 eV excitation at Nabs = 0.4 x 10^15 cm^-2; Drude fits of temperature-dependent Delta sigma(omega).

Temperature: 77-287 K reported in figure; text discusses 78 K and 287 K
Atmosphere: vacuum cryostat below 1 x 10^-4 mbar
Geometry: contact-free THz transmission through thin film
Context: pristine Cu3BHT film
Measurement source: 5 · Crossover from non-equilibrium to quasi-equilibrium regime · Fig. 3d,e

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Critical energy from temperature-gamma Arrhenius relation	8 +/- 2 meV (65 +/- 15 cm-1)	65 cm-1	+/- 2 meV; +/- 15 cm-1	Text Exact Reported	6 · Crossover from non-equilibrium to quasi-equilibrium regime · Fig. 3e; Supplementary Fig. 2
Charge scattering rate gamma at 287 K	~50 THz at 287 K	—	—	Text Approximate	6 · Crossover from non-equilibrium to quasi-equilibrium regime · Fig. 3e; Supplementary Fig. 12
Charge scattering rate gamma at low temperature	~30 THz at 78 K	—	—	Text Approximate	6 · Crossover from non-equilibrium to quasi-equilibrium regime · Fig. 3e; Supplementary Fig. 12