Patents by Inventor Sanjay Kumar Srivastava

Sanjay Kumar Srivastava has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10811546
    Abstract: A process of depositing zirconium oxide (ZrO2) layers possessing dual properties of anti-reflection and passivation of silicon surfaces, including passivation of n-type and p-type silicon substrates. To grow a ZrO2 anti-reflection passivation layer, a precursor layer of zirconium oxide is spun on a silicon surface then dried, pyrolyzed and fired at suitable contact firing conditions, avoiding additional deposition. Thermal annealing in a hydrogen environment improves passivation quality of ZrO2 layer to a level 3-4 times higher than that of fired films alone. ZrO2 dielectric passivation layers exhibit improved passivation quality after illumination due to photo-enhanced passivation and higher passivation quality at higher thermal budget suitable for screen printed metal contact firing, unlike standard PECVD deposited passivation layers. The method is adaptable for fabrication of silicon solar cells and other structures utilizing passivated layers.
    Type: Grant
    Filed: November 22, 2016
    Date of Patent: October 20, 2020
    Assignee: Council of Scientific & Industrial Research
    Inventors: Prathap Pathi, Rani Kalpana, Vandana, Sanjay Kumar Srivastava, Chandra Mohan Singh Rauthan, Parakram Kumar Singh
  • Publication number: 20180351010
    Abstract: A process of depositing zirconium oxide (ZrO2) layers possessing dual properties of anti-reflection and passivation of silicon surfaces, including passivation of n-type and p-type silicon substrates. To grow a ZrO2 anti-reflection passivation layer, a precursor layer of zirconium oxide is spun on a silicon surface then dried, pyrolyzed and fired at suitable contact firing conditions, avoiding additional deposition. Thermal annealing in a hydrogen environment improves passivation quality of ZrO2 layer to a level 3-4 times higher than that of fired films alone. ZrO2 dielectric passivation layers exhibit improved passivation quality after illumination due to photo-enhanced passivation and higher passivation quality at higher thermal budget suitable for screen printed metal contact firing, unlike standard PECVD deposited passivation layers. The method is adaptable for fabrication of silicon solar cells and other structures utilizing passivated layers.
    Type: Application
    Filed: November 22, 2016
    Publication date: December 6, 2018
    Applicant: Council of Scientific & Industrial Research
    Inventors: Prathap Pathi, Rani Kalpana, Sanjay Kumar Srivastava, Chandra Mohan Singh Rauthan, Parakram Kumar Singh
  • Patent number: 8022055
    Abstract: The invention relates to novel betulinic acid derivatives of formula (I), wherein R is C(?CH2)CH3 or CH(CH3)2; R2 together with the adjacent carbonyl group forms a carboxylic acid, carboxylic acid ester or amide or substituted amide; R3 or R4 are hydrogen or aryl with the proviso that both are not independently hydrogen or alkyl or R3 and R4 are combined together to form an aryl ring optionally substituted with a group X, wherein X is selected from halogen, alkyl, cyano, nitro, alkoxy, amino or substituted amine; Y is N or O; and R1 is zero when Y is O, and R1 is hydrogen, alkyl or aryl alkyl when Y is N, useful for inhibition of tumor cancer cells.
    Type: Grant
    Filed: December 29, 2005
    Date of Patent: September 20, 2011
    Assignee: Dabur Pharma Limited
    Inventors: Rama Mukherjee, Sanjay Kumar Srivastava, Mohammad Jamshed Ahmed Siddiqui, Manu Jaggi, Anu T. Singh, Anand Vardhan, Manoj Kumar Singh, Praveen Rajendran, Hemant Kumar Jajoo, Anand C. Burman, Vivek Kumar, Nidhi Rani, Shiv Kumar Agarwal
  • Patent number: 7501443
    Abstract: This invention generally relates to the derivatives of 3.6-disubstituted azabicyclo [3.1.0] hexanes of the following formula [IA]. The compounds of this invention can function as muscarinic receptor antagonists, and can be used for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems mediated through muscarinic receptors. The invention also relates to a process for the preparation of the compounds of the present invention, pharmaceutical compositions containing the compounds of the present invention and the :h1ethods for treating the diseases mediated through muscarinic receptors.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: March 10, 2009
    Assignee: Ranbaxy Laboratories Limited
    Inventors: Anita Mehta, Sanjay Kumar Srivastava, Jang Bahadur Gupta