Substitution defect enhancing thermoelectric properties in CuInTe2

Synergistic Regulation of Phonon and Electronic Properties to Improve the Thermoelectric Performance of Chalcogenide CuIn1−xGaxTe2:yInTe (x = 0–0.3) with In Situ Formed Nanoscale Phase InTe

“…Figure 2c showcases that the power factor (PF = α 2 σ) follows the trend of the electrical conductivity. The highest PF value is 13.8 μW cm −1 K −2 for the sample at x = 0.2 and 687 K. This value is much higher than those of most pure CuInTe 2 or its based chalcogenides reported (3.82–11.7 μW cm −1 K −2 ) and comparable to those of Cu 0.95(6) InTe 2 (13.0–13.7 μW cm −1 K −2 ) and Cu 0.95(6) InTe 2 + In 2 O 3 (14.45μW cm −1 K −2 ) . However, the PF value is much lower than the estimated value of CuInTe 2 (PF > 26 μW cm −1 K −2 at 800 K), suggesting that there is still a big room for the enhancement.…”

“…The increasing in DOS substantiates the increasing of the Seebeck coefficient, [15] and the narrowing of the bandgap may stabilize the transport of carriers. In order to confirm this assumption, we present the Pisarenko plot of the sample CuIn 1−x Ga x Te 2 :yInTe (x = 0.3) using the single parabolic band (SPB) model by taking an effective mass m *0 = 2.7 m o in Figure 5a, where the data circled in a wine dotted line is related to the pristine CuInTe 2 that mostly obeys the Pisarenko relation (SPB model) from different experiments [1,9,31,36,40,41,47] for comparison. In order to confirm this assumption, we present the Pisarenko plot of the sample CuIn 1−x Ga x Te 2 :yInTe (x = 0.3) using the single parabolic band (SPB) model by taking an effective mass m *0 = 2.7 m o in Figure 5a, where the data circled in a wine dotted line is related to the pristine CuInTe 2 that mostly obeys the Pisarenko relation (SPB model) from different experiments [1,9,31,36,40,41,47] for comparison.…”

“…Consequently, the peak ZT value enhances to 1.22 at ≈850 K. [1,9,31,36,40,41,47] (circled by wine dotted line) are presented for comparison with those of the present data (hollow symbols circled by gray shaded area); b) Lattice thermal conductivities at 319 and 605 K as a function of x value in CuIn 1−x Ga x Te 2 : yInTe, compared with the calculation data based on modified model (SCEMT) for the (CuIn 1 − x Ga x Te 2 ):y(InTe) composites. This nano phase InTe plays a predominant role in reducing the lattice thermal conductivity at low and middle temperatures.…”

“…Generally, the α value increases with increase in Ga content (x value), and it converges gradually above ≈680 K at x ≤ 0.2. 2020, 6,1901141 reported (3.82-11.7 µW cm −1 K −2 ) [2,10,30,[33][34][35][36][39][40][41][42] and comparable to those of Cu 0.95(6) InTe 2 (13.0-13.7 µW cm −1 K −2 ) [1,9] and Cu 0.95(6) InTe 2 + In 2 O 3 (14.45µW cm −1 K −2 ). The electrical conductivity (σ) increases as the x value increases before it starts to fall at x > 0.2, and at x = 0.3 the electrical conductivity decreases significantly, as shown in Figure 2b.…”

Inorganic thermoelectric materials: A review

“…The mechanism of reducing κ lat by point defects mainly comes from the large mass and strain fluctuations between the guest and the host atoms. These fluctuations could be enhanced by using interstitial atoms, creating vacancies or by substitution of atoms in TE materials . Besides, dislocation arrays are usually used to scatter mid‐range frequency phonons.…”