Bio


Kunal Mukherjee is an assistant professor in Materials Science and Engineering at Stanford. He has been an assistant professor in the Materials department at UC Santa Barbara (2016-2020), held postdoctoral appointments at IBM TJ Watson Research Center (2016) and MIT (2015), and worked as a transceiver engineer at Finisar (2009-2010).

The Mukherjee group specializes in semiconductors that emit and detect light in the infrared. Our research enables better materials for data transmission, sensing, manufacturing, and environmental monitoring. We make high-quality thin films with IV-VI (PbSnSe) and III-V (GaAs-InAs/GaSb) material systems and spend much of our time understanding how imperfections in the crystalline structure such as dislocations and point defects impact their electronic and optical properties. This holds the key to directly integrating these semiconductors with silicon and germanium substrates for new hybrid circuits that combine infrared photonics and conventional electronics.

Academic Appointments


Honors & Awards


  • Reid and Polly Anderson Faculty Fellow, Stanford University (2020-2022)
  • CAREER Award, National Science Foundation (2020)
  • Corbett Prize, International Conference on Defects in Semiconductors (2019)
  • PhD Fellowship, IBM (2014)
  • Graduate Fellowship, Singapore-MIT Alliance (2007)
  • President's Research Scholar, Nanyang Technological University (2004)

Boards, Advisory Committees, Professional Organizations


  • Member, Materials Research Society (2012 - Present)

Professional Education


  • Ph. D., Massachusetts Institute of Technology, Materials Science and Engineering (2014)
  • S. M., National University of Singapore, Advanced Materials for micro- and nano-systems (2009)
  • M. Eng., Massachusetts Institute of Technology, Materials Science and Engineering (2008)
  • B. Eng., Nanyang Technological University, Singapore, Electrical and Electronics (2007)

2020-21 Courses


Stanford Advisees


  • Doctoral Dissertation Advisor (AC)
    Jarod Meyer
  • Master's Program Advisor
    Louie Zhong

All Publications


  • Engineering quantum-coherent defects: The role of substrate miscut in chemical vapor deposition diamond growth APPLIED PHYSICS LETTERS Meynell, S. A., McLellan, C. A., Hughes, L. B., Wang, W., Mates, T. E., Mukherjee, K., Jayich, A. 2020; 117 (19)

    View details for DOI 10.1063/5.0029715

    View details for Web of Science ID 000594750600001

  • Defect filtering for thermal expansion induced dislocations in III-V lasers on silicon APPLIED PHYSICS LETTERS Selvidge, J., Norman, J., Hughes, E. T., Shang, C., Jung, D., Taylor, A. A., Kennedy, M. J., Herrick, R., Bowers, J. E., Mukherjee, K. 2020; 117 (12)

    View details for DOI 10.1063/5.0023378

    View details for Web of Science ID 000574437300001

  • A Pathway to Thin GaAs Virtual Substrate on On-Axis Si (001) with Ultralow Threading Dislocation Density PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE Shang, C., Selvidge, J., Hughes, E., Norman, J. C., Taylor, A. A., Gossard, A. C., Mukherjee, K., Bowers, J. E. 2020
  • Recombination-enhanced dislocation climb in InAs quantum dot lasers on silicon JOURNAL OF APPLIED PHYSICS Mukherjee, K., Selvidge, J., Jung, D., Norman, J., Taylor, A. A., Salmon, M., Liu, A. Y., Bowers, J. E., Herrick, R. W. 2020; 128 (2)

    View details for DOI 10.1063/1.5143606

    View details for Web of Science ID 000553055500001

  • Nucleation control and interface structure of rocksalt PbSe on (001) zincblende III-V surfaces PHYSICAL REVIEW MATERIALS Haidet, B. B., Hughes, E. T., Mukherjee, K. 2020; 4 (3)
  • Development of Lattice-Mismatched GaInAsP for Radiation Hardness IEEE JOURNAL OF PHOTOVOLTAICS France, R. M., Espinet-Gonzalez, P., Haidet, B. B., Mukherjee, K., Guthrey, H. L., Atwater, H. A., Walker, D. 2020; 10 (1): 103–8
  • Defects in Cd3As2 epilayers via molecular beam epitaxy and strategies for reducing them PHYSICAL REVIEW MATERIALS Rice, A. D., Park, K., Hughes, E. T., Mukherjee, K., Alberi, K. 2019; 3 (12)
  • III/V-on-Si MQW lasers by using a novel photonic integration method of regrowth on a bonding template LIGHT-SCIENCE & APPLICATIONS Hu, Y., Liang, D., Mukherjee, K., Li, Y., Zhang, C., Kurczveil, G., Huang, X., Beausoleil, R. G. 2019; 8: 93

    Abstract

    Silicon photonics is becoming a mainstream data-transmission solution for next-generation data centers, high-performance computers, and many emerging applications. The inefficiency of light emission in silicon still requires the integration of a III/V laser chip or optical gain materials onto a silicon substrate. A number of integration approaches, including flip-chip bonding, molecule or polymer wafer bonding, and monolithic III/V epitaxy, have been extensively explored in the past decade. Here, we demonstrate a novel photonic integration method of epitaxial regrowth of III/V on a III/V-on-SOI bonding template to realize heterogeneous lasers on silicon. This method decouples the correlated root causes, i.e., lattice, thermal, and domain mismatches, which are all responsible for a large number of detrimental dislocations in the heteroepitaxy process. The grown multi-quantum well vertical p-i-n diode laser structure shows a significantly low dislocation density of 9.5 × 104 cm-2, two orders of magnitude lower than the state-of-the-art conventional monolithic growth on Si. This low dislocation density would eliminate defect-induced laser lifetime concerns for practical applications. The fabricated lasers show room-temperature pulsed and continuous-wave lasing at 1.31 μm, with a minimal threshold current density of 813 A/cm2. This generic concept can be applied to other material systems to provide higher integration density, more functionalities and lower total cost for photonics as well as microelectronics, MEMS, and many other applications.

    View details for DOI 10.1038/s41377-019-0202-6

    View details for Web of Science ID 000489749400002

    View details for PubMedID 31645936

    View details for PubMedCentralID PMC6804852

  • Growth and Magnetotransport in Thin-Film alpha-Sn on CdTe PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS Vail, O., Taylor, P., Folkes, P., Nichols, B., Haidet, B., Mukherjee, K., de Coster, G. 2020; 257 (1)
  • Non-radiative recombination at dislocations in InAs quantum dots grown on silicon APPLIED PHYSICS LETTERS Selvidge, J., Norman, J., Salmon, M. E., Hughes, E. T., Bowers, J. E., Herrick, R., Mukherjee, K. 2019; 115 (13)

    View details for DOI 10.1063/1.5113517

    View details for Web of Science ID 000487997400031

  • Phase Stability and Diffusion in Lateral Heterostructures of Methyl Ammonium Lead Halide Perovskites ACS APPLIED MATERIALS & INTERFACES Kennard, R. M., Dahlman, C. J., Nakayama, H., DeCrescent, R. A., Schuller, J. A., Seshadri, R., Mukherjee, K., Chabinyc, M. L. 2019; 11 (28): 25313–21

    Abstract

    Mixed halide hybrid organic-inorganic perovskites have band gaps that span the visible spectrum making them candidates for optoelectronic devices. Transport of the halide atoms in methyl ammonium lead iodide (MAPbI3) and its alloys with bromine has been observed in both dark and under illumination. While halide transport upon application of electric fields has received much attention, less is known regarding bromide and iodide interdiffusion down concentration gradients. This work provides an upper bound on the bromide-iodide interdiffusion coefficient Di in thin films of MAPb(Br x I1-x)3 using a diffusion couples of lateral heterostructures. The upper bound of Di was extracted from changes in the interface profiles of the heterostructures upon exposure to heat. The stability of thoroughly heated interfacial profiles suggests that the miscibility gap extends to higher temperatures and to a higher fractional composition of bromine than predicted by theory. The results of this work provide guidance for compositions of thermally stable heterostructures of hybrid halide perovskites.

    View details for DOI 10.1021/acsami.9b06069

    View details for Web of Science ID 000476684900051

    View details for PubMedID 31268293

  • Glide of threading dislocations in (In)AlGaAs on Si induced by carrier recombination: Characteristics, mitigation, and filtering JOURNAL OF APPLIED PHYSICS Hughes, E. T., Shah, R. D., Mukherjee, K. 2019; 125 (16)

    View details for DOI 10.1063/1.5088844

    View details for Web of Science ID 000466779900048

  • Anomalous tilting in InGaAs graded buffers from dislocation sources at wafer edges JOURNAL OF CRYSTAL GROWTH Mukherjee, K., Vaisman, M., Callahan, P. G., Lee, M. 2019; 512: 169–75
  • Fast Diffusion and Segregation along Threading Dislocations in Semiconductor Heterostructures NANO LETTERS Bonef, B., Shah, R. D., Mukherjee, K. 2019; 19 (3): 1428–36

    Abstract

    Heterogeneous integration of semiconductors combines the functionality of different materials, enabling technologies such as III-V lasers and solar cells on silicon and GaN LEDs on sapphire. However, threading dislocations generated during the epitaxy of these dissimilar materials remain a key obstacle to the success of this approach due to reduced device efficiencies and reliability. Strategies to alleviate this and understand charge carrier recombination at threading dislocations now need an accurate description of the structure of threading dislocations in semiconductor heterostructures. We show that the composition around threading dislocations in technologically important InGaAs/GaAs/Ge/Si heterostructures are indeed different from that of the matrix. Site-specific atom probe tomography enabled by electron channeling contrast imaging reveals this at individual dislocations. We present evidence for the simultaneous fast diffusion of germanium and indium up and down a dislocation, respectively, leading to unique compositional profiles. We also detect the formation of clusters of metastable composition at the interface between Ge and GaAs, driven by intermixing in these two nearly immiscible materials. Together, our results have important implications for the properties of dislocations and interfaces in semiconductors and provide new tools for their study.

    View details for DOI 10.1021/acs.nanolett.8b03734

    View details for Web of Science ID 000461537600003

    View details for PubMedID 30742447

  • Contribution of top barrier materials to high mobility in near-surface InAs quantum wells grown on GaSb(001) PHYSICAL REVIEW MATERIALS Lee, J., Shojaei, B., Pendharkar, M., Feldman, M., Mukherjee, K., Palmstrom, C. J. 2019; 3 (1)
  • Recent Advances in InAs Quantum Dot Lasers Grown on On-Axis (001) Silicon by Molecular Beam Epitaxy PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE Jung, D., Norman, J., Wan, Y., Liu, S., Herrick, R., Selvidge, J., Mukherjee, K., Gossard, A. C., Bowers, J. E. 2019; 216 (1)
  • Direct observation of recombination-enhanced dislocation glide in heteroepitaxial GaAs on silicon PHYSICAL REVIEW MATERIALS Callahan, P. G., Haidet, B. B., Jung, D., Seward, G. E., Mukherjee, K. 2018; 2 (8)
  • Recombination activity of threading dislocations in GaInP influenced by growth temperature JOURNAL OF APPLIED PHYSICS Mukherjee, K., Reilly, C. H., Callahan, P. G., Seward, G. E. 2018; 123 (16)

    View details for DOI 10.1063/1.5018849

    View details for Web of Science ID 000431147200155

  • Low threading dislocation density GaAs growth on on-axis GaP/Si (001) JOURNAL OF APPLIED PHYSICS Jung, D., Callahan, P. G., Shin, B., Mukherjee, K., Gossard, A. C., Bowers, J. E. 2017; 122 (22)

    View details for DOI 10.1063/1.5001360

    View details for Web of Science ID 000418349300058

  • Rapid imaging of misfit dislocations in SiGe/Si in cross-section and through oxide layers using electron channeling contrast APPLIED PHYSICS LETTERS Mukherjee, K., Wacaser, B. A., Bedell, S. W., Sadana, D. K. 2017; 110 (23)

    View details for DOI 10.1063/1.4984210

    View details for Web of Science ID 000403347700011

  • Direct-Gap 2.1-2.2 eV AlInP Solar Cells on GaInAs/GaAs Metamorphic Buffers IEEE JOURNAL OF PHOTOVOLTAICS Vaisman, M., Mukherjee, K., Masuda, T., Yaung, K., Fitzgerald, E. A., Lee, M. 2016; 6 (2): 571–77
  • Praseodymium Cuprate Thin Film Cathodes for Intermediate Temperature Solid Oxide Fuel Cells: Roles of Doping, Orientation, and Crystal Structure. ACS applied materials & interfaces Mukherjee, K., Hayamizu, Y., Kim, C. S., Kolchina, L. M., Mazo, G. N., Istomin, S. Y., Bishop, S. R., Tuller, H. L. 2016; 8 (50): 34295–302

    Abstract

    Highly textured thin films of undoped, Ce-doped, and Sr-doped Pr2CuO4 were synthesized on single crystal YSZ substrates using pulsed laser deposition to investigate their area-specific resistance (ASR) as cathodes in solid-oxide fuel cells (SOFCs). The effects of T' and T* crystal structures, donor and acceptor doping, and a-axis and c-axis orientation on ASR were systematically studied using electrochemical impedance spectroscopy on half cells. The addition of both Ce and Sr dopants resulted in improvements in ASR in c-axis oriented films, as did the T* crystal structure with the a-axis orientation. Pr1.6Sr0.4CuO4 is identified as a potential cathode material with nearly an order of magnitude faster oxygen reduction reaction kinetics at 600 °C compared to thin films of the commonly studied cathode material La0.6Sr0.4Co0.8Fe0.2O3-δ. Orientation control of the cuprate films on YSZ was achieved using seed layers, and the anisotropy in the ASR was found to be less than an order of magnitude. The rare-earth doped cuprate was found to be a versatile system for study of relationships between bulk properties and the oxygen reduction reaction, critical for improving SOFC performance.

    View details for DOI 10.1021/acsami.6b08977

    View details for PubMedID 27998143

  • Spontaneous lateral phase separation of AlInP during thin film growth and its effect on luminescence JOURNAL OF APPLIED PHYSICS Mukherjee, K., Norman, A. G., Akey, A. J., Buonassisi, T., Fitzgerald, E. A. 2015; 118 (11)

    View details for DOI 10.1063/1.4930990

    View details for Web of Science ID 000361843300046

  • Improved photoluminescence characteristics of order-disorder AlGaInP quantum wells at room and elevated temperatures APPLIED PHYSICS LETTERS Mukherjee, K., Deotare, P. B., Fitzgerald, E. A. 2015; 106 (14)

    View details for DOI 10.1063/1.4917254

    View details for Web of Science ID 000352820700019

  • Effects of dislocation strain on the epitaxy of lattice-mismatched AlGaInP layers JOURNAL OF CRYSTAL GROWTH Mukherjee, K., Beaton, D. A., Mascarenhas, A., Bulsara, M. T., Fitzgerald, E. A. 2014; 392: 74–80
  • Determination of the direct to indirect bandgap transition composition in AlxIn1-xP JOURNAL OF APPLIED PHYSICS Beaton, D. A., Christian, T., Alberi, K., Mascarenhas, A., Mukherjee, K., Fitzgerald, E. A. 2013; 114 (20)

    View details for DOI 10.1063/1.4833540

    View details for Web of Science ID 000327697600010

  • Amber-green light-emitting diodes using order-disorder AlxIn1-xP heterostructures JOURNAL OF APPLIED PHYSICS Christian, T. M., Beaton, D. A., Mukherjee, K., Alberi, K., Fitzgerald, E. A., Mascarenhas, A. 2013; 114 (7)

    View details for DOI 10.1063/1.4818477

    View details for Web of Science ID 000323510900075

  • Growth, microstructure, and luminescent properties of direct-bandgap InAlP on relaxed InGaAs on GaAs substrates JOURNAL OF APPLIED PHYSICS Mukherjee, K., Beaton, D. A., Christian, T., Jones, E. J., Alberi, K., Mascarenhas, A., Bulsara, M. T., Fitzgerald, E. A. 2013; 113 (18)

    View details for DOI 10.1063/1.4804264

    View details for Web of Science ID 000319294100026

  • Silicon CMOS Ohmic Contact Technology for Contacting III-V Compound Materials ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY Pacella, N. Y., Mukherjee, K., Bulsara, M. T., Fitzgerald, E. A. 2013; 2 (7): P324–P331
  • Electron transport in electrospun TiO2 nanofiber dye-sensitized solar cells APPLIED PHYSICS LETTERS Mukherjee, K., Teng, T., Jose, R., Ramakrishna, S. 2009; 95 (1)

    View details for DOI 10.1063/1.3167298

    View details for Web of Science ID 000267983200033