Use of a flexible thermoelectric source is a feasible approach to realizing selfpowered wearable electronics and the Internet of Things.Inorganic thin films are promising candidates for fabricating flexible power supp...Use of a flexible thermoelectric source is a feasible approach to realizing selfpowered wearable electronics and the Internet of Things.Inorganic thin films are promising candidates for fabricating flexible power supply,but obtaining highthermoelectric‐performance thin films remains a big challenge.In the present work,a p‐type Bi_(x)Sb_(2−x)Te_(3) thin film is designed with a high figure of merit of 1.11 at 393 K and exceptional flexibility(less than 5%increase in resistance after 1000 cycles of bending at a radius of∼5 mm).The favorable comprehensive performance of the Bi_(x)Sb_(2−x)Te_(3) flexible thin film is due to its excellent crystallinity,optimized carrier concentration,and low elastic modulus,which have been verified by experiments and theoretical calculations.Further,a flexible device is fabricated using the prepared p‐type Bi_(x)Sb_(2−x)Te_(3) and n‐type Ag_(2)Se thin films.Consequently,an outstanding power density of∼1028μWcm^(−2)is achieved at a temperature difference of 25 K.This work extends a novel concept to the fabrication of highperformance flexible thin films and devices for wearable energy harvesting.展开更多
The exploration of genetically variable accessions is the key source of germplasm conservation and potential breeding material for the future. The more diverse group of cultivars provides an ample opportunity to breed...The exploration of genetically variable accessions is the key source of germplasm conservation and potential breeding material for the future. The more diverse group of cultivars provides an ample opportunity to breeders for releasing new and superior varieties, considering their quality traits for direct commercial utilization. In this study, we assessed the genetic diversity of Cicer arietinum 70 accessions from Pakistan and USA using morphological traits, seed protein and molecular markers. Based on four morphological traits, the average coefficient of variation was calculated as 56.8% with significant correlation among yield traits. The analysis revealed that the accessions 1898, 2819, 3022, 3037, 3040, 3043, 3054, 3059 and 3063 were best in performance with a total of 12% environmental error. The cluster analysis based on protein data revealed 50% genetic diversity among accessions. The clustering pattern did not show any grouping that could be attributed to either the geographic distribution or the field performance. For molecular characterization of germplasm 5 PCR based RAPD primers, OPA4, OPA9, OPG13, UBC181 and UBC733b used were found to be polymorphic with 37% genetic diversity among local and exotic accessions. Whereas, 3 SSR primers viz., CaSTMS2, Ca- STMS15 and CaSTMS21 scored the genetic variability up to 55% by cluster analysis through UPGMA percent disagreement. The primers, TA72 and TA130 were linked with yield related traits, indicated highest dissimilarity index value (0.69) and notable variation in the identified promising lines. The Morphometric, Biochemical and Molecular markers reported here, are helpful to assess the extent of genetic diversity among Chickpea accessions and can be used to identify the unreported cultivars with desirable quantitative traits for improving Chickpea yield in Pakistan. Based on the study, the accessions 3043 and 3054 have been recommended to the breeders for their future use in multiplication and screening against various diseases.展开更多
BiSe with intrinsic low thermal conductivity has considered as a promising thermoelectric(TE)material at nearly room temperature.To improve its low thermoelectric figure of merit(zT),in this work,Sb and Te isovalent c...BiSe with intrinsic low thermal conductivity has considered as a promising thermoelectric(TE)material at nearly room temperature.To improve its low thermoelectric figure of merit(zT),in this work,Sb and Te isovalent co-alloying was performed and significantly optimized its TE property with weakly anisotropic characteristic.After substituting Sb on Bi sites,the carrier concentration is suppressed by introduction of Sbsingle bond Se site defects,which contributes to the increased absolute value of Seebeck coefficient(|S|).Further co-alloying Te on Se of the optimized composition Bi_(0.7)Sb_(0.3)Se,the carrier concentration increased without affecting the|S|due to the enhanced effective mass,which leads to a highest power factor of 12.8μW/(cm·K^(2))at 423 K.As a result,a maximum zT of∼0.54 is achieved for Bi_(0.7)Sb_(0.3)Se_(0.7)Te_(0.3) along the pressing direction and the average zT(zTave)(from 300 K to 623 K)are drastically improved from 0.24 for pristine BiSe sample to 0.45.Moreover,an energy conversion efficiency∼4.0%is achieved for a single leg TE device of Bi_(0.7)Sb_(0.3)Se_(0.7)Te_(0.3)when applied the temperature difference of 339 K,indicating the potential TE application.展开更多
Thermoelectric thin film has attracted a lot of attention due to its potential in fabricating micropower generator in chip sensors for internet of things(IoT).However,the undeveloped performance of n-type thermoelectr...Thermoelectric thin film has attracted a lot of attention due to its potential in fabricating micropower generator in chip sensors for internet of things(IoT).However,the undeveloped performance of n-type thermoelectric thin film limits its widely application.In this work,a facile post-selenization diffusion reaction method is employed to introduce Se into Bi_(2)Te_(3)thin films,in order to optimize the carrier transport properties.Experimental and theoretical calculation results indicate that the carrier concentration decreases and density of states increases after Se doping,leading to the enhancement of Seebeck coefficient.Further,adjusting the diffusion reaction temperature can maintain the carrier concentration while increasing the mobility simultaneously,resulting in a high power factor of 1.5 mW/(m·K^(2)),which is eight times higher than that of the pristine Bi_(2)Te_(3)thin films.Subsequently,a thin film device fabricated by the present Se-doped Bi_(2)Te_(3)thin films shows the highest output power of 60.20 nW under the temperature difference of 37 K,indicating its potential for practical use.展开更多
Bi_(2)O_(2)Se is considered one of the most promising thermoelectric(TE)materials for combining with p-type BiCuSeO in a TE module given its unique chemical and thermal stability.However,the enhancement of its dimensi...Bi_(2)O_(2)Se is considered one of the most promising thermoelectric(TE)materials for combining with p-type BiCuSeO in a TE module given its unique chemical and thermal stability.However,the enhancement of its dimensionless figure of merit,zT value,remains a challenge because of its low electrical conductivity.Herein,we introduce KCl into Bi_(2)O_(2)Se,synthesized by solid-state reaction and spark plasma sintering method,to improve its TE properties.The synthesized samples show an outstanding enhancement in electrical conductivity,carrier concentration,and power factor after KCl doping.The Bi_(2)O_(2)Se-based sample with a 0.05%KCl doping content possesses a high zT value of~0.58 at 773 K,which is over 50%enhancement compared with the pristine Bi_(2)O_(2)Se sample.We also prove that the K element substitutes the Bi site,and Cl replaces the Se site by X-ray diffraction results and density functional theory calculation,supporting that K can improve the electrical conductivity by the position of Fermi level which is above the conduction band minimum.Experimental and theoretical results indicate the success of co-doping with a small amount of KCl and show a huge potential of this novel method for Bi_(2)O_(2)Se TE performance improvement.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:62274112Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2022A1515010929Science and Technology Plan project of Shenzhen,Grant/Award Numbers:JCYJ20220531103601003,20220810154601001。
文摘Use of a flexible thermoelectric source is a feasible approach to realizing selfpowered wearable electronics and the Internet of Things.Inorganic thin films are promising candidates for fabricating flexible power supply,but obtaining highthermoelectric‐performance thin films remains a big challenge.In the present work,a p‐type Bi_(x)Sb_(2−x)Te_(3) thin film is designed with a high figure of merit of 1.11 at 393 K and exceptional flexibility(less than 5%increase in resistance after 1000 cycles of bending at a radius of∼5 mm).The favorable comprehensive performance of the Bi_(x)Sb_(2−x)Te_(3) flexible thin film is due to its excellent crystallinity,optimized carrier concentration,and low elastic modulus,which have been verified by experiments and theoretical calculations.Further,a flexible device is fabricated using the prepared p‐type Bi_(x)Sb_(2−x)Te_(3) and n‐type Ag_(2)Se thin films.Consequently,an outstanding power density of∼1028μWcm^(−2)is achieved at a temperature difference of 25 K.This work extends a novel concept to the fabrication of highperformance flexible thin films and devices for wearable energy harvesting.
文摘The exploration of genetically variable accessions is the key source of germplasm conservation and potential breeding material for the future. The more diverse group of cultivars provides an ample opportunity to breeders for releasing new and superior varieties, considering their quality traits for direct commercial utilization. In this study, we assessed the genetic diversity of Cicer arietinum 70 accessions from Pakistan and USA using morphological traits, seed protein and molecular markers. Based on four morphological traits, the average coefficient of variation was calculated as 56.8% with significant correlation among yield traits. The analysis revealed that the accessions 1898, 2819, 3022, 3037, 3040, 3043, 3054, 3059 and 3063 were best in performance with a total of 12% environmental error. The cluster analysis based on protein data revealed 50% genetic diversity among accessions. The clustering pattern did not show any grouping that could be attributed to either the geographic distribution or the field performance. For molecular characterization of germplasm 5 PCR based RAPD primers, OPA4, OPA9, OPG13, UBC181 and UBC733b used were found to be polymorphic with 37% genetic diversity among local and exotic accessions. Whereas, 3 SSR primers viz., CaSTMS2, Ca- STMS15 and CaSTMS21 scored the genetic variability up to 55% by cluster analysis through UPGMA percent disagreement. The primers, TA72 and TA130 were linked with yield related traits, indicated highest dissimilarity index value (0.69) and notable variation in the identified promising lines. The Morphometric, Biochemical and Molecular markers reported here, are helpful to assess the extent of genetic diversity among Chickpea accessions and can be used to identify the unreported cultivars with desirable quantitative traits for improving Chickpea yield in Pakistan. Based on the study, the accessions 3043 and 3054 have been recommended to the breeders for their future use in multiplication and screening against various diseases.
基金This work was supported by the National Natural Science Foundation of China(No.52372210 and No.52072248)Natural Science Foundation of Guangdong Province of China(No.2023A1515010122 and No.2021A1515012128)Technology plan project of Shenzhen(No.20220810154601001).
文摘BiSe with intrinsic low thermal conductivity has considered as a promising thermoelectric(TE)material at nearly room temperature.To improve its low thermoelectric figure of merit(zT),in this work,Sb and Te isovalent co-alloying was performed and significantly optimized its TE property with weakly anisotropic characteristic.After substituting Sb on Bi sites,the carrier concentration is suppressed by introduction of Sbsingle bond Se site defects,which contributes to the increased absolute value of Seebeck coefficient(|S|).Further co-alloying Te on Se of the optimized composition Bi_(0.7)Sb_(0.3)Se,the carrier concentration increased without affecting the|S|due to the enhanced effective mass,which leads to a highest power factor of 12.8μW/(cm·K^(2))at 423 K.As a result,a maximum zT of∼0.54 is achieved for Bi_(0.7)Sb_(0.3)Se_(0.7)Te_(0.3) along the pressing direction and the average zT(zTave)(from 300 K to 623 K)are drastically improved from 0.24 for pristine BiSe sample to 0.45.Moreover,an energy conversion efficiency∼4.0%is achieved for a single leg TE device of Bi_(0.7)Sb_(0.3)Se_(0.7)Te_(0.3)when applied the temperature difference of 339 K,indicating the potential TE application.
基金the Technology Plan Project of Shenzhen(20220810154601001 and JCYJ20220531103601003)National Natural Science Foundation of China(No.62274112)Guangdong Basic and Applied Basic Research Foundation(2019A1515110107 and 2022A1515010929)。
文摘Thermoelectric thin film has attracted a lot of attention due to its potential in fabricating micropower generator in chip sensors for internet of things(IoT).However,the undeveloped performance of n-type thermoelectric thin film limits its widely application.In this work,a facile post-selenization diffusion reaction method is employed to introduce Se into Bi_(2)Te_(3)thin films,in order to optimize the carrier transport properties.Experimental and theoretical calculation results indicate that the carrier concentration decreases and density of states increases after Se doping,leading to the enhancement of Seebeck coefficient.Further,adjusting the diffusion reaction temperature can maintain the carrier concentration while increasing the mobility simultaneously,resulting in a high power factor of 1.5 mW/(m·K^(2)),which is eight times higher than that of the pristine Bi_(2)Te_(3)thin films.Subsequently,a thin film device fabricated by the present Se-doped Bi_(2)Te_(3)thin films shows the highest output power of 60.20 nW under the temperature difference of 37 K,indicating its potential for practical use.
基金supported by the National Natural Science Foundation of China(No.62274112)the National Natural Science Foundation of Guangdong Province of China(Nos.2022A1515010929 and 2023A1515010122)+1 种基金the Science and Technology Plan Project of Shenzhen(No.JCYJ20220531103601003)In addition,the authors are thankful for the assistance on HAADF-STEM observation received from the Electron Microscope Center of Shenzhen University.
文摘Bi_(2)O_(2)Se is considered one of the most promising thermoelectric(TE)materials for combining with p-type BiCuSeO in a TE module given its unique chemical and thermal stability.However,the enhancement of its dimensionless figure of merit,zT value,remains a challenge because of its low electrical conductivity.Herein,we introduce KCl into Bi_(2)O_(2)Se,synthesized by solid-state reaction and spark plasma sintering method,to improve its TE properties.The synthesized samples show an outstanding enhancement in electrical conductivity,carrier concentration,and power factor after KCl doping.The Bi_(2)O_(2)Se-based sample with a 0.05%KCl doping content possesses a high zT value of~0.58 at 773 K,which is over 50%enhancement compared with the pristine Bi_(2)O_(2)Se sample.We also prove that the K element substitutes the Bi site,and Cl replaces the Se site by X-ray diffraction results and density functional theory calculation,supporting that K can improve the electrical conductivity by the position of Fermi level which is above the conduction band minimum.Experimental and theoretical results indicate the success of co-doping with a small amount of KCl and show a huge potential of this novel method for Bi_(2)O_(2)Se TE performance improvement.
