Send customer account creation email to admin

Question

I want to send account creation notification email to admin .

I followed following code. events.xml path Namespace/Modulename/etc

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="customer_register_success">
        <observer name="sendmail_toadmin" instance="Namespace\Modulename\Observer\SendMailToAdmin"/>
    </event>
</config>

SendMailToAdmin.php path Namespace/Modulename/Observer

namespace Namespace\Modulename\Observer;

use Magento\Framework\Event\ObserverInterface;

class SendMailToAdmin implements ObserverInterface
{

    const XML_PATH_EMAIL_RECIPIENT = 'trans_email/ident_general/email';
    protected $_transportBuilder;
    protected $inlineTranslation;
    protected $scopeConfig;
    protected $storeManager;
    protected $_escaper;

    public function __construct(
        \Magento\Framework\Mail\Template\TransportBuilder $transportBuilder,
        \Magento\Framework\Translate\Inline\StateInterface $inlineTranslation,
        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
        \Magento\Store\Model\StoreManagerInterface $storeManager,
        \Magento\Framework\Escaper $escaper
    ) {
        $this->_transportBuilder = $transportBuilder;
        $this->inlineTranslation = $inlineTranslation;
        $this->scopeConfig = $scopeConfig;
        $this->storeManager = $storeManager;
        $this->_escaper = $escaper;
    }

    public function execute(\Magento\Framework\Event\Observer $observer)
    {


        $customer = $observer->getData('customer');

        $this->inlineTranslation->suspend();
        try 
        {
            $error = false;

            $sender = [
                'name' => $this->_escaper->escapeHtml($customer->getFirstName()),
                'email' => $this->_escaper->escapeHtml($customer->getEmail()),
            ];
            $postObject = new \Magento\Framework\DataObject();
            $postObject->setData($sender);
            $storeScope = \Magento\Store\Model\ScopeInterface::SCOPE_STORE; 
            $transport = 
                $this->_transportBuilder
                ->setTemplateIdentifier('1') // Send the ID of Email template which is created in Admin panel
                ->setTemplateOptions(
                    ['area' => \Magento\Framework\App\Area::AREA_FRONTEND, // using frontend area to get the template file
                    'store' => \Magento\Store\Model\Store::DEFAULT_STORE_ID,]
                )
                ->setTemplateVars(['data' => $postObject])
                ->setFrom($sender)
                ->addTo($this->scopeConfig->getValue(self::XML_PATH_EMAIL_RECIPIENT, $storeScope))
                ->getTransport();
            $transport->sendMessage(); ;
            $this->inlineTranslation->resume();


        } 
        catch (\Exception $e) 
        {
            \Magento\Framework\App\ObjectManager::getInstance()->get('Psr\Log\LoggerInterface')->debug($e->getMessage());
        }

    }

}